Employees pass beneath pipes leading to oil storage tanks at the central processing plant for oil and gas at the Salym Petroleum Development oil fields near the Bazhenov shale formation in Salym, Russia.

President Joe Biden on Tuesday announced that the U.S. will ban imports of Russian oil, a major escalation in the international response to Moscow's invasion of Ukraine.

The move came as Western-allied nations work to sever Moscow from the global economy to punish Russian President Vladimir Putin for his unprovoked aggression.

"Today I am announcing the United States is targeting the main artery of Russia's economy. We're banning all imports of Russian oil and gas and energy," Biden said at the White House. "That means Russian oil will no longer be acceptable at U.S. ports and the American people will deal another powerful blow to Putin's war machine."

"This is a step we're taking to inflict further pain on Putin," Biden said.

The United Kingdom announced its own restrictions on buying Russian oil imports just before Biden spoke, saying it will phase out the country's imports by the end of the year. The European Union earlier Tuesday morning unveiled a plan to wean itself off of Russian fossil fuels.

"We simply cannot rely on a supplier who explicitly threatens us," European Commission President Ursula von der Leyen said in a press release announcing the plan.