RTSXKES
A general view shows a newly built section of the U.S.-Mexico border fence at Sunland Park, U.S. opposite the Mexican border city of Ciudad Juarez, Mexico Thursday. Reuters

Shortly after President Donald Trump announced his plan to build a wall between the United States and Mexico, his administration forced the Border Patrol chief to resign, an official told the Associated Press.

Mark Morgan, a former FBI agent who took the position in October, told senior Border Patrol agents he was asked to leave and decided to resign rather than protest the ouster during a video conference Thursday. His last day will be Tuesday.

Morgan’s appointment had caused a stir in the agency, as he had never held a position with the Border Patrol before. The agency’s union wrote on its official website that it was “disappointed” Morgan was chosen over more senior members and that his appointment broke with “92 years of tradition.”

Acting commissioner of the U.S. Customs and Border Protection agency Kevin K. McAllenan removed Morgan this week, and an unnamed official told the Washington Post that the move was “a change in leadership.” However, the source could not state the reason for Morgan’s ouster or confirm who was behind it.

The union endorsed Trump during his campaign last year.

“The union has been very vocal about someone from outside of the Border Patrol becoming the head of the Border Patrol,” ex-commissioner of the U.S. Customs and Border Protection Gil Kerlikowske told the Post. “The union supported this candidate for president, and now very much appears to be directing things — which is absolutely unheard of in law enforcement. The union used their influence to have him removed.’’

The union had been lobbying Trump’s transition officials to remove Morgan because it thought he “did not make border security a priority,” National Border Patrol Council president Brandon Judd told the Post.

Trump’s plan for the wall, which has not been officially been given the go-ahead, faced significant criticism during his campaign and, most recently, over how his administration planned to pay for it. Mexican President Enrique Pena Nieto has said repeatedly his country will not finance the massive structure, which would have to cover 1,900 miles and could cost between $10 billion and $25 billion.