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.

In the English countryside Saturday, European officials presented their case to Vice President JD Vance in a hastily arranged meeting. The leaders of several European nations said afterward that while they supported Trump’s diplomatic efforts, any peace talks must be preceded by a ceasefire and Ukraine itself must be actively involved.

Ukrainian President Volodymyr Zelensky was not named as a participant in the Alaska summit, to take place Friday between Trump and Putin. However, the White House has not completely ruled out including Zelensky in some meetings, two sources familiar with the matter told CNN. One White House official stressed that anything involving Zelensky would likely happen after the Trump-Putin meeting.

The summit has come together very quickly, and details are still in flux. An exact location has yet to be announced.

A White House official said Trump remained “open to a trilateral summit with both leaders” but that “the White House is planning the bilateral meeting requested by President Putin.”

Since Trump unveiled plans to meet with Putin in a post to social media Friday, there has been an intensive diplomatic effort behind the scenes to get US allies on board.

Trump’s announcement notably did not say whether or when Zelensky would be included in the process. Zelensky and European leaders, meanwhile, have been emphatic that Ukraine needs to be part of any discussions about ending the war.