Mr. Bailey, a Republican, has been an active ally of Mr. Trump’s, and veterans of his office have taken significant roles in the administration, including D. John Sauer, who now serves as the solicitor general of the United States, overseeing the Trump administration’s arguments before the Supreme Court.

Trump interrupted his talks in Washington with European leaders to call Putin, an EU diplomat told Reuters. Zelenskiy posted that today marked "a demonstration of genuine unity between Europe and the United States.