The Biden administration has imposed some of its toughest sanctions yet on Russia, in a move designed to hit Moscow's energy revenues that fuel its war in Ukraine.
The measures target more than 200 legal entities and individuals, ranging from traders and officials to insurance companies, as well as hundreds of oil tankers.
For the first time since Moscow's all-out invasion of Ukraine, the UK will join the US in directly sanctioning the energy companies Gazprom Neft and Surgutneftegaz.
“Taking over Russian oil companies will drain Russia's military assets – and every ruble we take off Putin's hands helps save Ukrainian lives,” Foreign Secretary David Lammy said.
Some of the measures announced by the U.S. Treasury Department on Friday will be signed into law, meaning the incoming Trump administration will need to involve Congress if it wants to overturn them.
Washington is also trying to severely limit who can legally buy Russian energy and is going after what it has called Moscow's “shadow fleet” of ships that transport oil around the world.
US Treasury Secretary Janet Yellen said the actions “increase the risk of sanctions related to Russia's oil trade, including shipping and financial facilities to support Russian oil exports.”
President Joe Biden said Russian leader Vladimir Putin was in “tough shape,” adding that “it's really important that he doesn't have any breathing space to continue to do the terrible things that he continues to do.”
“Gas prices (in the United States) are likely to go up three or four cents a gallon,” the president said.
But, he added, the measures are likely to “have a profound effect on the growth of the Russian economy.”
Ukrainian President Volodymyr Zelensky thanked the US for what he called its “bipartisan support”.
Since the beginning of the war in Ukraine, oil price ceiling is among the key measures designed to curb Russia's energy exports.
But as Olga Hakova of the Atlantic Council's Global Energy Center explained, it is performance was “diluted” because it was also trying to avoid the decline in the volume of Russian oil on the market.
This is due to concerns about the impact that reduced supply would have on the global economy.
But experts said the oil market was now in a healthier position.
“U.S. oil production (and exports) are at record levels and rising, so the price impact of taking Russian oil out of the market, the target of today's sanctions, will be mitigated,” said Daniel Fried, senior fellow at the Atlantic Council.
“The U.S. government is going after the Russian oil sector in a big way, intending to deliver what could be a heavy blow,” Freed added.
John Herbst, a former US ambassador to Ukraine, said that while the steps were “excellent”, their implementation would be critical.
“Which means the Trump administration will determine whether these measures are really putting pressure on the Russian economy,” he said.