On Sunday, Secretary of State Marco Rubio, who sat in on the meetings with Mr. Putin at the American air base outside of Anchorage, disputed the idea that the Europeans were coming as a posse to protect Mr. Zelensky from a repeat of the February shouting match.

The documents reportedly included plans for a canceled luncheon, seating charts, a gift presentation and phone numbers for U.S. and Russian officials.

European leaders will join Ukraine’s President Volodymyr Zelenskyy for his crucial meeting with President Donald Trump, European Commission President Ursula von der Leyen said on Sunday.