Brendan Hoffman/Getty Images

(NEW YORK) -- Russian forces are continuing their attempted push through Ukraine from multiple directions, while Ukrainians, led by President Volodymyr Zelenskyy, are putting up "stiff resistance," according to U.S. officials.

The attack began Feb. 24, when Russian President Vladimir Putin announced a "special military operation."

Russian forces moving from neighboring Belarus toward Ukraine's capital, Kyiv, don't appear to have advanced closer to the city since coming within about 20 miles, although smaller advanced groups have been fighting gun battles with Ukrainian forces inside the capital since at least Friday.

Russia has been met by sanctions from the United States, Canada and countries throughout Europe, targeting the Russian economy as well as Putin himself.

Here's how the news is developing. All times Eastern:

Mar 07, 8:21 pm
Officials concerned Russia may strike supply line to Ukraine

There have been monumental efforts, especially by Poland, to get weapons into Ukraine and to the front lines.

But a senior official told ABC News there are indications Russia may attack one of those supply chains in Poland before it gets to Ukraine, potentially using air power.

Russian forces have created heavily fortified areas from which to launch long-range artillery, the official said, meaning they can shell cities from a distance rather than send troops into them. Ukrainian President Volodymyr Zelenskyy has repeatedly requested air power assistance in order to destroy these fortified areas.

Ukrainians have seen success in attacking Russian resupply areas, mostly in the north but also among smaller, moving groups.

-ABC News’ Chief Global Affairs Correspondent Martha Raddatz

Mar 07, 7:46 pm
Zelenskyy appears in his office for 1st time since invasion began

Ukrainian President Volodymyr Zelenskyy has filmed himself from the street just outside his office, but for the first time since the invasion began, he posted a video message from inside.

“We’re not scared, because you’re not scared,” he told Ukrainians who have taken up arms and told Russia it is not welcome.

“So, I stay here at Bankova Street,” Zelenskyy said. “I’m not hiding from anyone and not afraid of anyone as long as it takes to win in this war, our truly patriotic war.”

The latest address was filmed as a selfie in which he showed a view of Kyiv on Monday night.

“This is Kyiv at night outside the window. This is our office. Monday night. You know, we’re used to saying Monday is a hard day,” he said. “But the country is at war now, so every day is Monday.”

-ABC News’ Christine Theodorou

Mar 07, 7:23 pm
Nuclear research facility damaged by shelling in Kharkiv

Ukraine’s national nuclear regulator told the International Atomic Energy Agency on Monday that a new nuclear research facility producing radioisotopes for medical and industrial applications had been damaged by shelling in the city of Kharkiv on Sunday.

The incident did not cause any increase in radiation levels at the site.

The nuclear material in the facility is always subcritical, the IAEA said, and the inventory of radioactive material is very low, so the damage reported would not have any radiological consequence.

Eight of Ukraine’s 15 reactors are currently operating, the IAEA said, citing Ukraine’s nuclear regulator.

IAEA Director General Grossi noted there have been several episodes compromising safety at Ukraine’s nuclear sites, including a recent fire at the Zaporizhzhya Nuclear Power Plant, where two reactors are still operational.

-ABC News’ Christine Theodorou

Mar 07, 7:14 pm
Ukraine and Russia’s foreign ministers to meet this week

Ukraine and Russia’s foreign ministers have agreed to meet on the sidelines of a diplomatic forum in Turkey on Thursday in what will be the highest level direct meeting between the two sides since Russia’s invasion.

The meeting was agreed following a call between Turkish President Recep Tayyip Erdogan and Russian President Vladimir Putin on Sunday.

Russia’s foreign ministry spokesperson Maria Zakharova earlier confirmed the two had agreed to a meeting. Ukraine’s foreign minister Dmytro Kuleba has also confirmed it.

It’s not clear that there is much the two will be able to agree on, but it still signals a readiness by Russia to talk. For now, Russia is continuing to put forward hardline demands that Ukraine guarantee it will never join NATO or the European Union.

-ABC News’ Patrick Reevell

Mar 07, 6:53 pm
Russia declares temporary cease-fire, claims it will not send in conscripts

Russia’s military has announced another temporary cease-fire in Ukraine beginning Tuesday at 10 a.m. and said it is prepared to open humanitarian corridors from Kyiv and several other key Ukrainian cities it has encircled.

In a statement, Russia’s defense ministry said the corridors would allow people to go north to Russia and its ally Belarus, adding that it would also allow routes in some places to other parts of Ukraine.

The ministry said there will be corridors from Kyiv, as well as the northern cities Chernihiv and Sumy and the key eastern cities Kharkiv and Mariupol.

Russia had initially proposed corridors only to Russia and Belarus, which Ukraine had rejected as “immoral.”

However, Russia has previously violated its own cease-fire, shelling evacuation areas, and it is unclear if corridors for people to move within Ukraine will actually be made available.

Russian President Vladimir Putin also said in a video address that Russia will not call up additional reservists or send in conscripts to fight the war in Ukraine, saying it will be fought only by professional soldiers.

“The tasks are solved only by professional military personnel,” Putin said. “I am sure they will reliably ensure security and peace for the people of Russia.”

His comments came in a video message to Russia’s women on International Women’s Day, saying he understood the concerns of the “mothers, wives, sisters, brides and girlfriends of our soldiers and officers who are now in battle, defending Russia during a special military operation.”

Some reports indicate that Russian conscripts have been pressured into signing professional contracts before being deployed into Ukraine.

-ABC News’ Patrick Reevell and Tanya Stukalova

Mar 07, 6:16 pm
White House responds to Zelenskyy’s criticism

After Ukrainian President Volodymyr Zelenskyy told ABC News’ David Muir that he believes President Joe Biden can do more to facilitate getting Polish fighter jets to Ukraine, the Biden administration said it is ultimately up to Poland.

“This is Poland’s sovereign decision to make,” White House press secretary Jen Psaki told ABC News’ Cecilia Vega. “We have in no way opposed Poland transferring planes to Ukraine.”

Psaki said there are “practical questions” to consider, such as how the planes would be transferred and where they would depart from and land. She also noted that procuring new planes and transferring serious weapons systems often takes years -- so a speedy transfer would represent a major challenge.

Vega asked Psaki if it was just logistical issues or whether Biden was concerned that supplying planes to Poland would “exacerbate the conflict.”

The press secretary said there are logistical challenges and that they’re “looking at all of those factors.”

“But we are not certainly preventing or blocking or discouraging Poland,” Psaki said. “That is, they are a sovereign country. They make their own decisions, but it is not as easy as moving planes around.”

-ABC News’ Sarah Kolinovsky

Mar 07, 5:08 pm
New York City on 'ultra-high alert' for cyberattacks from Russia

New York City has gone from a "high alert" to an "ultra-high alert" for potential cybersecurity attacks on critical city infrastructure following the Russian cyber-aggression in Ukraine, a New York Police Department official said Monday.

NYPD Deputy Commissioner John Miller said during a news conference that normally the city is on "high alert" for cyberattacks, but a difference between "high" and "ultra-high" alerts is that they can attribute possible cyber threats to "state actors." When tensions rise between the United States and Russia, so does the threat for tactical and strategic cyberattacks, Miller said.

"There is no guarantee that those attacks will be limited to Ukraine," Gillibrand said. "The decision to impose sanctions on Russia puts the country at an increased risk that Russia will carry out retaliatory cyberattacks, particularly against New York state infrastructure and individuals."

When asked during the news conference if there have been any potential direct Russian cyberattacks against New York, New York City Chief Technology Officer Matthew Fraser said, “we have seen an uptick [in cyber threats], but we are not aware of any campaign that's explicitly targeting the city itself."

-ABC News' Victoria Arancio

Mar 07, 3:36 pm
Nearly 100% of committed Russian combat power in Ukraine: US defense official

A senior U.S. defense official said on Monday that Russian President Vladimir Putin has committed nearly "100% of his combat power" into Ukraine.

"We now assess that Mr. Putin has committed nearly 100% of his combat power into Ukraine. And by combat power, I mean that combat power that he had amassed along the border with Ukraine and in Belarus," the defense official said.

The official also said reports that Russia is attempting to recruit Syrians to sign up and fight in Ukraine appear to be accurate.

"We find that noteworthy that he (Putin) believes that he needs to rely on foreign fighters to supplement what is a very significant commitment of combat power inside Ukraine as it is," the official said.

The official said Russia has launched more than 625 missiles against Ukraine since the invasion began on Feb. 4. He said Russia has increased its use of "long-range fires" to compensate for a lack of movement in its forces on the ground.

"So, we certainly have noticed increases in what we call long-range fires -- bombardment, rocket attacks, artillery, as well as missile strikes," the official said.

-ABC News' Matthew Seyler

Mar 07, 3:14 pm
3rd round of Russia-Ukraine cease-fire talks end

The third round of cease-fire talks between Ukraine and Russia took place in Belarus Monday and produced incremental steps forward, according to the lead Ukrainian negotiator.

Following the meeting, the third in eight days, lead Ukrainian negotiator Mykhailo Podolyak tweeted, "There are small positive movements forward in improving the logistics of humanitarian corridors... Intensive consultations have continued on the basic political block of the regulations, along with a ceasefire and security guarantees."

Ukrainian authorities have claimed efforts to evacuate its citizens out of the country have been disrupted by Russian forces shelling the humanitarian corridors Moscow agreed to in a cease-fire.

-ABC News' Patrick Reevell

Mar 07, 1:33 pm
EXCLUSIVE: Zelenskyy tells David Muir why no-fly zone is necessary

In an exclusive interview with ABC News anchor David Muir, Ukraine President Volodymyr Zelenskyy stressed that the United States and NATO should establish a no-fly zone over his country to stop Russian missiles from hitting civilian targets like a university dormitory and a pediatric clinic.

"Mr. President, as you know, the president [Joe Biden] and NATO have said no to this no-fly zone because of concerns this could trigger a much wider ... conflict, a much bigger war than what we're seeing already because there would have to be a willingness to shoot Russian planes outta the sky. Do you understand that concern?" Muir asked.

Zelenskyy, speaking to Muir from the Presidential Office in Kyiv, said that while Biden and NATO have refused to impose a no-fly zone, Russian missiles continue to target civilians, adding that he believes Russian missiles should be shot out of the sky.

"You have to preserve lives. There ... were simply kids there with tumors," Zelenskyy said of the missile strike on the pediatric clinic. "And in the university, there were ordinary students. I'm sure that the brave American soldiers who would be shooting it down knowing that it is flying towards the students, I'm sure that they had no doubt in doing so."

Mar 07, 12:18 pm
White House mulling Russian oil ban without European allies participating: Official

The White House indicated on Monday that it was considering a ban on Russian oil even without the support of its European allies, an official with the National Security Council told ABC News.

Europe relies much more on Russian oil and gas than the United States does and would likely see much higher prices if such a significant chunk of their energy imports were suddenly cut off.

If the United States banned Russian oil imports without Europe doing the same, the impact on Russia would be much smaller than if the U.S. and Europe worked in concert. Russia exported 1% of its oil exports to the United States in 2020.

Moving forward without Europe would also be a departure from Biden’s approach of working in lockstep with Europe on sanctions against Russia.

Bloomberg reported Sunday night that the Biden administration was weighing this move.

Mar 07, 12:13 pm
Zelenskyy tells David Muir path to peace 'more difficult' than acknowledging Putin's ultimatums

In an exclusive interview Monday with ABC News anchor David Muir, Ukraine President Volodymyr Zelenskyy said the path to peace is "more difficult than simply acknowledging" another ultimatum from Russian President Vladimir Putin.

Zelenskyy spoke with Muir from the Presidential Office in Kyiv and said he will stay in his country for the duration of the war.

"When the Kremlin says these three conditions to end the war … that you must give up on joining NATO, recognize Crimea as part of Russia and recognize the independence of those two separatist regions in the east … you say it’s a nonstarter, not willing to [accept] those three conditions right now?" Muir asked.

Zelenskyy responded, "It is more difficult than simply acknowledging them ... this is another ultimatum and we are not prepared for ultimatums."

He went on, "But we have the possible solution resolution for these three items, key items, what needs to be done is for President Putin to start talking. Start the dialogue instead of living in the information bubble without oxygen. I think that’s where he is. He is in this bubble. He’s getting this information and you don’t know how realistic that information is that he’s getting."

Mar 07, 11:04 am
Biden to speak with UK, French and German counterparts about Ukraine

President Joe Biden is scheduled to hold a secure video teleconference Monday morning with leaders of France, Germany and the United Kingdom to discuss the latest developments regarding Russia and Ukraine, according to the White House.

Biden is expected to be in the White House Situation Room when he participates in a teleconference with French President Emmanuel Macron, German Chancellor Olaf Scholz and British Prime Minister Boris Johnson, according to the White House.

The teleconference will be closed to the press and will occur after Biden received his daily intelligence briefing, the White House said.

Mar 07, 9:57 am
Putin falsely claims his forces are 'taking measures to save lives'

Russian President Vladimir Putin spoke with European Council President Charles Michel on Monday and according to a Kremlin readout of the conversation, falsely claimed Russian forces are “taking all possible measures to save the lives of civilians" in Ukraine.

Putin also repeated the Russian military’s claim that Ukrainian "nationalists" are preventing humanitarian corridors from being opened to allow the evacuation of civilians. But Ukrainian authorities have claimed efforts to evacuate its citizens out of the country have been disrupted by Russian forces shelling the humanitarian corridors Moscow agreed to in a cease-fire.

"The main threat comes from nationalist formations, which essentially use the tactics of terrorists, hiding behind the civilian population," Putin told Michel, according to the report.

The Russian president "called on the European Union to make a real contribution to saving people's lives, to put pressure on the Kyiv authorities and force them to respect humanitarian law," the Kremlin said in a statement.

-ABC News' Patrick Reevell

Mar 07, 7:42 am
Ukrainian foreign minister again calls for NATO no-fly zone

Ukrainian Minister of Foreign Affairs Dmytro Kuleba on Monday called for NATO to enforce a no-fly zone over Ukraine, saying Russian planes were targeting civilians.

"The Russian Air Force dominates in the skies and continues bombing our cities and killing many civilians," Kuleba told George Stephanopoulos on Good Morning America.

U.S. and NATO officials have rejected calls from Ukrainian officials to impose a no-fly zone, saying doing so could provoke Russia, perhaps pulling other European countries and NATO members into the conflict. The U.S. and NATO have offered other military aid, including a possible deal to send aircraft to Ukraine.

"We believe that the rejection of the idea of the no-fly zone is based in the lack of confidence in the strength of NATO as an alliance," Kuleba said. "Because the military might of NATO is incomparably bigger compared to Russia. So why would Russia dare to shoot down a NATO plane, knowing it is doomed, eventually doomed, if a war with NATO begins."

Kuleba over the weekend had urged the international community to help in the struggle against “Russian barbarians.” He posted a photo on Twitter on Sunday of an unexploded bomb, which he said landed on a residential building in Chernihiv.

Mar 07, 5:50 am
Ukraine casts doubt on Russian pledge for civilian pathways

Ukrainian officials said Russia’s proposal on Monday to open "humanitarian corridors" for cities in Ukraine is not a genuine offer because it offers to evacuate civilians only to Belarus and Russia.

Iryna Vereshchuk, a Ukrainian vice prime minister, in a televised briefing called that "unacceptable" and said Ukraine had demanded instead that civilians be allowed to evacuate to other parts of Ukraine.

Russia’s Defense Ministry had said it would open a corridor from towns and villages north of Kyiv, where heavy fighting is taking place, but that would allow people to travel to the Belarusian city of Gomel and then be flown to Russia. Russia also offered corridors near the besieged northeastern and eastern cities of Kharkiv, Sumy and Mariupol, but that would also only allow people to leave over the border to Russia.

"This is an unacceptable option of humanitarian corridors. Our people from outskirts of Kyiv won’t go to Belarus and then to Russia," Vereshchuk said.

She said that Ukraine wants civilians north of Kyiv to be permitted to leave to the capital and for those from Kharkiv to be allowed to western cities by train, and from Mariupol north to the central city of Zaporizhzhia.

"We delivered our proposal on how the corridors should be organized," Vereshchuk said, later adding, "Humanitarian aid is prepared for a number of towns in the east and south. We ask Russia to confirm these corridors and provide ceasefire."

Russia has repeatedly violated its own ceasefire since offering humanitarian corridors for Mariupol and another eastern town Volnovakha, including shelling evacuation points in Mariupol according to officials there. The Red Cross, which is trying to organize the evacuations, has said the agreements currently are too vague and without clear understandings for routes out.

Russia said Monday's offer for the corridors was made following a lengthy phone conversation between French President Emmanuel Macron and Russian President Vladimir Putin on Sunday.

Vereshchuk said Russia was trying to exploit Macron’s name for a disingenuous offer of corridors.

"I hope president Macron understands that his name and good intentions are manipulated by Russia," she said.

-ABC News’ Patrick Reevell

Mar 07, 3:43 am
Refugee arrivals to Poland top 1 million, guard says

More than 1 million people fleeing Ukraine have arrived in Poland since the Russian invasion began on Feb. 24, the Polish Border Guard said on Monday.

A record 142,000 people arrived on Sunday, the guard said on Twitter. On Monday, about 42,000 people had crossed the border before 7 a.m. local time.

As of Sunday, more than 1.5 million people had fled the war in Ukraine, marking the "fastest growing refugee crises in Europe since World War II," according to Filippo Grandi, the U.N. high commissioner for refugees.

Mar 07, 2:43 am
With attacks on TV towers, Russia seeks to isolate Ukrainians, UK says

Russian forces have attacked Ukrainian communications infrastructure to "reduce Ukrainian citizens' access to reliable news and information," the U.K. Ministry of Defence said on Monday.

"Russia reportedly struck a TV tower in Kharkiv yesterday, suspending broadcasting output," the Ministry’s update said.

Russian forces on March 1 struck a TV tower in Kyiv, the capital.

Mar 07, 2:18 am
Russia says cease-fire will allow evacuations from 4 cities

Russia declared a cease-fire starting Monday morning, opening humanitarian corridors for the evacuation of civilians from Kyiv, Mariupol, Kharkiv and Sumy, the Russian interagency humanitarian response staff in Ukraine said.

"Taking into account the disastrous humanitarian situation and its severe deterioration in the cities of Kyiv, Kharkiv, Sumy, and Mariupol, and also at French President Emmanuel Macron's personal request to Russian President Vladimir Putin, the Russian Armed Forces are declaring a ceasefire and opening humanitarian corridors for reasons of humanity starting 10:00 a.m. on March 7, 2022," the staff said.

Ukrainian officials in Mariupol said Russia broke planned cease-fires on Saturday and Sunday.

-ABC News’ Anastasia Bagaeva

Copyright © 2022, ABC Audio. All rights reserved.