U.S. President Donald Trump said on Tuesday that the United States would start imposing tariffs and other measures on Russia "10 days from today" if Moscow showed no progress toward ending its more than three-year-long war in Ukraine.

Earlier this month, Trump set a 50-day deadline for Russia to accept a ceasefire. Failure to do so, the president said, would prompt punishing new economic measures, among them secondary sanctions on nations doing business with Moscow.