"Kevin McAleenan has done a unique job as Acting Secretary of Homeland Security. We have worked well with the Border Crossings to come down," Trump tweeted, tapping McAleenan to lead the department earlier in the year this.
"Kevin now, after many years in Government, wants to spend more time with his family and go to the private sector," Trump tweeted. "Congratulations Kevin, on a job well done!"
Trump said he would introduce McAleenan's successor next week, adding: "There are so many amazing candidates!"
McAleenan recently accompanied Trump on a tour of a section of the border outside of San Diego, Calif.
But he was viewed skeptically by hard-line immigration advocates inside and outside the administration, and he admitted in a recent interview with The Washington Post that he could not control the message from his agency.
"I think words are important," McAleenan said. "If you alienate half of your audience by using your terminology, your ability to win an argument will be hindered."
Some of his critics accuse McAleenan of leaking information ahead of a planned immigration attack last year that forced the operation to be postponed. He denies the allegations, but underscores the degree to which he struggles to win in some influential voices within the administration.
He has faced further criticism from Democrats throughout his career for the treatment of migrant administration in detention centers near the border.
McAleenan worked for the FBI and for Customs and Border Protection (CBP) during the George W. Bush and Obama administrations. He rose to the top job at DHS after Trump insisted Nielsen did not want to carry out some of his policies.
His release was part of an agency overhaul designed by senior White House aide Stephen Miller  Stephen MillerOvernight Health Care: Trump Attacks & # 39; Medicare for All & # 39; in Florida | Law from separate children, families seeking damages | Vaping-related disease cases top 1,000 Lawsuit by & # 39; traumatized & # 39; separated children and families seeking damages from the Trump administration Trump suggested migrants shot in the leg: NYT MORE one of Trump's most influential advisers on immigration.
Most of the leading immigration enforcement jobs are filled with a basic act. Mark Morgan leads CBP on an acting basis, Matt Albence serves as acting director of Immigration and Customs Enforcement (ICE) and Ken Cuccinelli is the glowing head of Citizenship and Immigration Services (USCIS).
Cuccinelli appeared in particular. as the public face of Trump's immigration agenda, and could be a candidate to replace McAleenan. However, his appointment will likely remain on an artistic basis because many GOP senators are skeptical of his ability to confirm.