"There will be no on-the-job training", he said.
The president says first lady Melania Trump especially will miss Neilsen around the White House. The picks is another win for White House Chief of staff John Kelly, who previously served as the DHS secretary. She is the first nominee for the homeland security post who had served in the department, according to the statement.
In addition, Nielsen was the senior legislative policy director for the Transportation and Security Administration, which operates under DHS, during the Bush administration.
The big question is on whether or not he will succeed at sparking about order in the West Wing which is at the moment plagued by infighting and disorganization.
Elaine Duke has been serving as acting DHS secretary since Kelly departed the agency for the White House in July.
Mr. Kelly pushed hard for her selection, making a personal appeal to Mr. Trump during a monthslong search process.
Though the White House confirmed her nomination, the president gave an on-camera announcement Thursday afternoon.
Trump urged the Senate to "put politics aside" and swiftly confirm Nielsen "in light of the serious threats facing our country and the natural disaster recovery efforts".
Trump additionally commended Kelly, who had just finished briefing the press, for his role at the DHS and now at the White House, saying "He is one of the finest people I have ever had the privilege to know, and we are deeply fortunate that he is now here at the White House as our chief of staff". He then sung Nielsen's past work in his administration, and spoke of how thrilled he was to have her in this new position.