A diplomatic scramble unfolded Saturday after President Donald Trump announced he would meet his Russian counterpart, Vladimir Putin, next week in Alaska, as European leaders rushed to understand the terms of the meeting and ensure Ukraine was not being left out of discussions about its future.

The vice president said the White House was trying to determine “when these three leaders could sit down and discuss an end to this conflict.”

U.S. Ambassador to NATO Matthew Whitaker said “it’s possible” that Ukrainian President Volodymyr Zelensky attends the upcoming meeting between President Trump and Russian President Vladimir Putin in Alaska.