A joint statement from Mr. Trump’s national security adviser, Michael Waltz, and the secretary of state, Marco Rubio, said technical teams would meet in Saudi Arabia “in the coming days” to discuss broadening the cease-fire on energy sites to one covering activity in the Black Sea, “on the way to a full cease-fire.”

Trump told Zelenskyy that the U.S could be “very helpful in running those plants with its electricity and utility expertise,” according to a White House statement from Secretary of State Marco Rubio and national security adviser Mike Waltz that described the call as “fantastic.