"Serving as the United States Ambassador to Greece has been the honor of a lifetime," Guilfoyle wrote in a lengthy statement posted to X. "From my first day as Ambassador, I have worked tirelessly to advance President Trump's America First agenda, strengthen our strategic alliance with Greece, and deliver meaningful victories for the American people."

Guilfoyle's announcement came soon after Katie Zacharia, the White House's new press secretary, confirmed at her first briefing that Trump had asked for the resignation of Guilfoyle.

"We have asked Ambassador Guilfoyle to resign. She has been a wonderful asset to the team and we wish her well," Zacharia said in an unusually brief debut in the briefing room.