WASHINGTON (AP) — The Trump administration said it is seeing signs that its sanctions on major Russian oil producers are crimping the economic engine that has allowed Moscow to continue to fund its war in Ukraine.

Prices for Russian oil have plunged as Indian and Chinese buyers moved to comply with the sanctions before last week’s deadline for companies and banks to wind down business with Russian oil giants Rosneft and Lukoil, a senior Treasury Department official told reporters on a briefing call. The official spoke on condition of anonymity to describe private conversations between the department and foreign buyers.

The official said the buyers have said they planned to cancel, pause or seek ways out of their forward purchases of Russian oil because of the sanctions announced in October.

The United States is promoting the penalties as President Donald Trump’s envoy, Steve Witkoff, is trying to advance a plan aimed at ending the war.

The sanctions were intended to force Russian President Vladimir Putin to the negotiating table and bring an end to the war that began when Russia invaded in February 2022.