WASHINGTON (Reuters) - U.S. Border Patrol Chief Mark Morgan has been asked to step down as the agency moves toward tougher enforcement of immigration laws under the Trump administration, a Department of Homeland Security official told Reuters on Thursday.

Morgan, a longtime former Federal Bureau of Investigation official, is expected to leave his post by the end of the month, a spokesman for U.S. Customs and Border Protection said.

President Donald Trump announced a broad plan to crack down on border security on Wednesday, including directing the construction of a wall along the border with Mexico.

The border patrol union, which endorsed Trump’s presidential campaign and applauded his executive orders, had been critical of Morgan for supporting former President Barack Obama’s plans to safeguard certain undocumented immigrants from deportation.

The executive board of the National Border Patrol Council called Morgan arrogant and a “disgrace to the Border Patrol” in an opinion piece published by conservative website Breitbart News on Nov. 30.

Unlike many border patrol officers, Morgan did not climb the chain of command within the agency but spent most of his career with the FBI.

Acting U.S. Customs and Border Protection Commissioner Kevin McAleenan issued a statement thanking Morgan for his service.

“On behalf of the men and women of U.S. Customs and Border Protection and the U.S. Border Patrol, I want to thank Mark Morgan for his unwavering dedication to our border security mission, and recognize his life-long career in service to the nation,” the statement said.