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

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

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

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