Vice President Kamala Harris has scheduled a trip to Warsaw, Poland, and Bucharest, Romania, next week, according to her office.

Harris will meet with leaders of both countries from March 9 to March 11, deputy press secretary Sabrina Singh said in a statement.

"They will discuss our continuing support for the people of Ukraine through security, economic, and humanitarian assistance and our determination to impose severe economic consequences on Russia and those complicit in Russia’s invasion," she said.

"The vice president’s meetings will also focus on how the United States can further support Ukraine’s neighbors as they welcome and care for refugees fleeing violence," Singh added.

-ABC News' Ben Gittleson

The White House on Friday did not rule out banning Russian oil imports to the U.S., saying it was "looking at ways to reduce the import of Russian oil," but showed continued reluctance in light of the impact it would have on energy prices.

“We are considering a range of options, but what's really essential is that we maintain a steady supply of global energy,” Cecilia Rouse, the chair of the White House's Council of Economic Advisers, said at the White House press briefing.

Adding, “Energy is a global market and we do not want to disrupt that market.”

Bloomberg on Friday reported that “the administration is weighing a ban on U.S. imports of Russian crude oil,” and that “conversations are taking place within the administration and with the U.S. oil and gas industry on the impact such a move would have on American consumers and the global supply,” citing unnamed “people familiar with the matter."

An expert at GasBuddy told ABC News on Thursday that banning Russian oil imports would, in fact, likely raise gas prices in the U.S.

Psaki said there wasn’t any “outside event” for which the U.S. was waiting to implement a ban, but that the White House was “mindful of not taking steps” that would raise energy prices for Americans and that the U.S. also wanted to take steps in concert with allies.

There would be a much larger impact on energy prices in Europe, which is a lot more reliant on Russian oil, according to experts.

-ABC News' Ben Gittleson

Russia's state censor, Roskomnadzor, added Twitter to its list of banned sites in the country on Friday, following a request from the Russian prosecutor general.

Earlier Friday, Roskomnadzor banned Facebook as the Russian government moves to limit dissent over the war in Ukraine.

-ABC News' Patrick Reevell

Russia's representative to the United Nations on Friday reiterated the Kremlin's claim that Ukrainian forces were responsible for the attack on the Zaporizhzhia nuclear power plant.

The representative said Russian forces came under small arms fire by a "Ukrainian sabotage group" that was stationed in a training complex building on site.

The representative claimed that Russian troops returned fire, but that as they departed, Ukrainians set the building on fire.

The Russian representative claimed Ukrainian "radicals" are under the West's "close guardianship and protection," giving them "carte blanche," and allowing them to act like "ISIS terrorists" by "hiding behind civilians and placing heavy weaponry and multiple rocket launchers in residential areas."

Ukraine, the U.S. and its allies have denied these claims.

The UN relief chief also fact-checked the Russian delegate on Monday, saying Russia's claim about Ukraine placing weapons in civilian areas was false.

- ABC News' Conor Finnegan

The Russian forces charging toward Kyiv haven't made progress in the last day as they face Ukrainian resistance and low food and gas supply, a senior U.S. defense official told reporters Tuesday.

However, it could be a deliberate pause, the official said. "Part of the stall could be ... as a result of their own self-determined sort of pause in operations -- that they are possibly regrouping, rethinking, reevaluating," the official said.

The U.S. believes Russian forces "have committed now more than 80% of what was their pre-staged combat power," the official added.

The official said some Russian soldiers weren't told they were going into combat. The official said "not all of them were apparently fully trained and prepared."

The strong Ukrainian resistance has also hurt morale, according to the official.

Russia has now launched more than 400 missiles on Ukraine, the official said. The U.S. believes Russia has launchers that could be used for thermobaric weapons, but cannot confirm their use, the official said.

Russian forces are making the most progress in the south. Russians are attacking Kherson in south Ukraine, which "appears very much to be contested city at this point," the official said.

Russians are also approaching Mariupol in southeastern Ukraine, and while they haven't yet entered the city, "they are close enough now that they could attack Mariupol with long range fires," the official said.

Two towns on the path to Mariupol are believed to be occupied by the Russians, according to the official.

The U.S. believes the Russians hope to move north out of Mariupol up to the heavily-contested city of Kharkiv. The official said they believe Russian forces are trying to encircle Kharkiv.

The U.S. official noted that they've seen "certain risk-averse behavior by the Russian military" over the last week.

"Take the amphibious assault, for instance. They put those troops ashore a good 70 kilometers away from Mariupol because they knew Mariupol was going to be defended and they could put them ashore in an uncontested environment. And they still haven't reached Mariupol," the official said.

"They are not necessarily willing to take high risks with their own aircraft and their own pilots," the official said.

"And of course we're seeing that on the ground -- the fairly slow and steady progress that they have made, and you guys are seeing it for yourselves on the ground where ... units are surrendering, sometimes without a fight."

-ABC News' Matt Seyler