President Trump has selected acting Immigration and Customs Enforcement Director Mark Morgan to be the acting head the Department of Homeland Security agency that oversees all border and customs operations, according to a source with firsthand knowledge of the discussions.

The White House has not announced the decision yet, but an official told the Washington Examiner said Morgan has accepted the job.

Customs and Border Protection Commissioner John Sanders informed acting DHS Secretary Kevin McAleenan, his predecessor, on Monday he would be resigning July 5. Sanders shared the letter with the agency's 60,000 personnel Tuesday.

Morgan, who was recently tapped as acting director of ICE, had been serving as national chief of the U.S. Border Patrol for three months when Trump fired him at the beginning of 2017. Morgan emerged as a commentator on Fox News late last year and has since made a name for himself by endorsing Trump's policies. He was tapped as the temporary head of ICE in early May.

Morgan had no experience as a Border Patrol agent nor did he work for ICE prior to his current stint. He spent 11 years in the Marine Corps and 20 years in the FBI, and he was tapped in 2014 for assistant commissioner of Customs and Border Protection. In that role, he oversaw the Border Patrol's 20,000 personnel.

"It's gonna be Morgan," one official told the Washington Examiner earlier Tuesday. Two other officials said Morgan's name was one of the top two contenders.

The same official said the White House was originally pushing for Morgan to take over CBP in April when acting DHS Secretary Kevin McAleenan was promoted, but McAleenan opposed Morgan and won.

"Ultimately, it’s Trump’s decision," the source said. "McAleenan won the last fight, and now it looks like [Stephen] Miller’s gonna win this fight."

Miller runs immigration policy in the White House.

The White House has cycled through a large number of DHS officials since Trump took office 30 months ago. In that time, the number of people illegally crossing the southern border has gone from 45-year lows to near-record highs.