Joe Biden on Tuesday announced 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 Russia 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.

The White House said in a fact sheet that Biden will sign an executive order banning Russian oil, liquefied natural gas and coal imports to the U.S.

The ban on new Russian oil contracts “is immediate,” a senior Biden administration official told reporters later Tuesday.

No new contracts will be allowed, and existing contracts for Russian oil must be phased out within 45 days, the official said.

Ukrainian President Volodymyr Zelenskyy applauded Biden’s move on Twitter later Tuesday.

“Thankful for US and @POTUS personal leadership in striking in the heart of Putin’s war machine and banning oil, gas and coal from US market,” he said in a post. “Encourage other countries and leaders to follow.”

The U.S. imported about 672,000 barrels a day from Russia in 2021, according to figures from the Energy Information Administration. That amount makes up roughly 8% of the total U.S. imports of oil and refined products.

Most of the country’s crude oil and petroleum imports come from Canada, Mexico and Saudi Arabia, making the U.S. far less dependent on Russian oil than many of its European partners.

The news of the ban, confirmed to CNBC by two people familiar with the matter before Biden’s speech, sent oil prices soaring Tuesday morning.

The price on West Texas Intermediate crude futures, contracts for April oil deliveries, hit $129.44 a barrel. That level is just below a recent high of $130.50 a barrel hit on Monday, which at the time was the highest price on oil futures since 2008.

Putin’s actions have provoked an unprecedented international reaction, as dozens of countries slap crippling sanctions on the Kremlin, its ultra-rich oligarchs and even Putin himself. Russia’s currency has plummeted in value and its stock market has been closed since severe sanctions were announced by the West, while a growing list of companies have pulled their business out of the country.