European leaders are expected to travel to Washington early this week to discuss ways of ending the war, Trump has said
"Certain European leaders are coming over to our country on Monday or Tuesday individually," Trump said, without specifying which leaders. He also signalled that he would speak with Putin in the next couple of days.
In an interview with ABC News, Ukrainian president Volodymyr Zelensky urged European nations to fully stop buying Russian energy.
He said: "We have to stop [buying] any kind of energy from Russia, and by the way, anything, any deals with Russia. We can't have any deals if we want to stop them." He praised Trump's tariff strategy as "the right idea" to cut off Moscow's revenues.
Since its full-scale invasion of Ukraine in March 2022, Russia has earned around $985bn (£729bn) of oil and gas, according to the think tank the Centre for Research on Energy and Clean Air.
China and India have been the largest buyers, while the EU has significantly reduced - but not entirely halted - purchases. Brussels has pledged to phase out all Russian energy imports by 2027.
Despite mounting sanctions, Russia is working to expand its markets. At a meeting in Beijing last week, Moscow said it would increase supplies of gas to China.
Meanwhile, OPEC+, the group of oil-producing nations that includes Russia, has agreed to boost production, a move that could drive down global oil prices and complicate Western efforts to squeeze Moscow's finances.