Eighteen Trump administration appointees serving on the advisory boards of military service academies have either resigned from their positions or were terminated, following a request from the Biden administration earlier this week, a White House official said Friday.

The appointees had been serving on the advisory boards of the Air Force Academy, Naval Academy and U.S. Military Academy at West Point, with six on each board, according to the official, who was not authorized to speak publicly on the matter.

Among the Trump appointees were former White House counselor Kellyanne Conway, former White House press secretary Sean Spicer and former national security adviser H.R. McMaster.

On Wednesday, the White House defended the move, arguing that it was about qualifications and values, not politics.

“The president’s objective is what any president’s objective is: to ensure you have nominees and people serving on these boards who are qualified to serve on them and who are aligned with your values,” White House press secretary Jen Psaki told reporters. “And so, yes, that was an ask that was made.”

The boards are composed of members of Congress and presidential appointees. Board members serve for three years in an advisory capacity.

Conway had been appointed to the Air Force Academy Board of Visitors. Spicer, a Navy Reserve commander, had been serving on the Naval Academy’s advisory board. McMaster had been appointed to the advisory board at the U.S. Military Academy; the retired U.S. Army lieutenant general is a West Point graduate and previously taught history there.

Retired four-star Army Gen. Jack Keane also was appointed to the U.S. Military Academy Board.

Some of the Trump appointees who had been asked to resign responded by defiantly refusing to do so or by criticizing the Biden administration.

Conway, in response to the request, tweeted a letter to Biden in which she said: “I’m not resigning, but you should,” saying the White House action “seems petty and political, if not personal.”

Russ Vought, the former director of the Office of Management and Budget in the Trump administration, had been serving on the Naval Academy’s Board of Visitors. In a tweet earlier this week, he shared a copy of the letter requesting his resignation along with a defiant reply: “No. It’s a three-year term.”

Seung Min Kim contributed to this report.