The United States will ban imports of Russian oil and other energy products but will not be joined in doing so by European allies, President Joe Biden announced Tuesday.

“Today, I'm announcing the United States is targeting the main artery of Russia's economy," Biden told reporters during a press conference from the White House. "We're banning all imports of Russian oil and gas and energy."

Biden said the ban means the U.S. "will deal another powerful blow" to Russian President Vladimir Putin amid his invasion of neighboring Ukraine. The move is also expected to trigger sharply higher gasoline and other energy prices in the U.S. and worldwide.

"There will be cost as well here in the United States," he added. "Republicans and Democrats understand, alike, understand that."

The decision was made in "close consultation" with U.S. allies and partners around the world, particularly in Europe, according to Biden.

"Because a united response to Putin's aggression has been my overriding focus, to keep all NATO and all the EU and our allies totally united," he said. "We're moving forward, understanding that many of our European allies and partner may not be in a position to join us."

-ABC News' Ben Gittleson and Molly Nagle

The United Kingdom will phase out the import of Russian oil and oil products by the end of the year, as part of its sanctions on Moscow for invading Ukraine, U.K. Buiness Secretary Kwasi Kwarteng announced Tuesday.

"Beyond Russia, the vast majority of our imports come from reliable partners such as the US, Netherlands and the Gulf. We’ll work with them this year to secure further supplies," Kwarteng said on his official Twitter account.

Kwarteng noted that while the U.K. "is not dependent" on Russian natural gas, as it only makes up 4% of the U.K's supply, he is exploring options to "end this altogether."

"The market has already begun to ostracise Russian oil, with nearly 70% of it currently unable to find a buyer," he added.

-ABC News' Joe Simonetti

Yegor Gordeev, host of the Ukrainian television morning show "Breaking with 1+1," said he and his coworkers have had to evacuate the studio during broadcast several times as air raid sirens ring out across Kyiv.

"I'm not in studio, I'm in bomb shelter," Gordeev told ABC News' George Stephanopoulos during an interview Tuesday on "Good Morning America."

"In Ukraine, we have no shows now, we have no TV channels now, we have only one big broadcast for controlled information to audience, for communication with audience for everything," he added.

It was a bloody day in the Ukrainian capital, according to Gordeev. He said the Ukrainian Air Force shot down a Russian aircraft in the center of Kyiv early Tuesday morning, while a Russian rocket destroyed the city's largest bakery, killing 30 people.

Gordeev said he hopes for peace in his home country but he's "not sure."

"In 21st century, it's barbarian war," he said in disbelief. "Putin is unstoppable."

The Russian Ministry of Defense claimed Tuesday that Ukrainian authorities are "categorically against" evacuating residents of Kyiv, Chernihiv, Sumy, Kharkiv and Mariupol to Russia.

"The authorities in Kyiv are continuing to categorically reject all main routes of evacuation from Kyiv, Chernihiv, Sumy, Kharkiv, and Mariupol to the territory of the Russian Federation," Mikhail Mizintsev, head of the Russian National Defense Control Center, said at a press briefing.

The Russian defense ministry alleged that the Ukrainians only confirmed one of the 10 evacuation routes Russia proposed. The confirmed route is from the city of Sumy, through Poltava and to the border with Poland, Mizintsev said.

The Russian defense ministry also claimed that more than 2.5 million Ukrainians have asked to be evacuated to Russia.

"Following the past day, 2,541,367 appeals from individual Ukrainian citizens, as well as foreigners made via various communication channels requesting to save and evacuate them from 1,917 settlements in Ukraine have already been processed in our database," Mizintsev said.

The Russian defense ministry further alleged that checkpoints in Poland, Slovakia, Hungary, Moldova and Romania "were virtually ill prepared" to receive Ukrainian refugees.

"People are forced to leave their cars and walk on foot carrying their heavy bags. Lines are up to 40 kilometers long, and the crossing time is over two days," Mizintsev said.

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