President Trump said Tuesday that Russian President Vladimir Putin has 10 days to agree to a peace deal with Ukraine or face severe tariffs from the U.S.

“Ten days from today, and then, you know, we’re going to put on tariffs and stuff,” Mr. Trump told reporters aboard Air Force One on a flight from Scotland to Washington. “I don’t know if it’s going to affect Russia because he wants to, obviously, probably keep the war going, but we’re going to put on tariffs and various things that you put on. It may or may not affect them.”

The new deadline, which is far shorter than the 50-day window Mr. Trump announced on July 14, would give Russia until Aug. 8 to reach a deal with Ukraine. Mr. Trump had said Monday that he was thinking of moving up the deadline to 10 or 12 days.

Any imposition of new tariffs would mark a shift for the White House, which excluded Russia from the list of tariffs it imposed on virtually all of America’s trade partners in April. But Mr. Trump is hoping the threat of “secondary” tariffs on countries that trade with Russia, most notably China and India, could force those nations to pressure Russia to end the war.

When asked if he was worried that additional tariffs on Russia could impact global oil prices, Mr. Trump said he was not concerned about that. Russia is one of the world’s top oil producers.

Dmitry Medvedev, the deputy chairman of the Security Council of Russia, cautioned Monday that Mr. Trump’s demand that Moscow end the conflict in 10 to 12 days would not end well for the U.S.

“Trump’s playing the ultimatum game with Russia: 50 days or 10… He should remember 2 things: 1. Russia isn’t Israel or even Iran. 2. Each new ultimatum is a threat and a step towards war. Not between Russia and Ukraine, but with his own country,” Mr. Medvedev said in a post on X. “Don’t go down the Sleepy Joe road!”

Earlier this month, Mr. Trump said he would impose 100% secondary tariffs on Russia if it did not halt the fighting. The levies would fall on countries that buy Russian exports such as oil, which Washington and Ukraine’s Western allies view as tacit support for Russia.

• Jeff Mordock can be reached at jmordock@washingtontimes.com.