More than 3 1/2 years into the war, the effort remains a cat-and-mouse game, with Russia finding new ways to get around sanctions, and Washington and Brussels adding new ones and looking for ways to plug enforcement gaps.
The chief target of the latest round: Russia's biggest oil companies, Rosneft and Lukoil. New U.S. Treasury sanctions threaten their customers in India and China with retaliation that could include being sanctioned themselves.
Meanwhile, the EU is phasing out shipments of Russian liquefied natural gas and is going after cryptocurrency issuers, platforms and exchanges that Russia has used to skirt restrictions on its financial dealings with the outside world.
U.S. Treasury Secretary Scott Bessent said the move aimed to push Russian President Vladimir Putin to agree to President Donald Trump's proposals for an "immediate ceasefire" in Ukraine.
"Given President Putin's refusal to end this senseless war, Treasury is sanctioning Russia's two largest oil companies that fund the Kremlin's war machine," he said, adding that "Treasury is prepared to take further action if necessary."