President Obama nominated a former attorney for the Defense Department as his new Secretary of Homeland Security, a job that Obama said is a "difficult and extraordinary mission."
Obama called Jeh Johnson -- who served under Obama in the Pentagon -- an "absolutely critical member of my national security team."
He said as the Pentagon's top lawyer, Johnson "helped design and implement many of the policies that have kept our country safe, including our success in dismantling the core of al- Qaida and the Fatah."
He called on Congress to confirm Johnson quickly, saying he has "been there, in the situation room, at the table in moments of decision."
He noted that Johnson had worked as a member of the Pentagon's senior management team, first under Bob Gates, and then under Leon Panetta, overseeing the work of more than 3 million military and civilian personnel.
"And I think it's fair to say that both former Secretaries Gates and Panetta will attest to the incredible professionalism that Jeh brings to the job, and the bipartisan approach that appropriately he takes when it comes to national security," Obama said.
He noted Johnson had also guided the report that Congress later used to repealing Don't Ask, Don't Tell.
Johnson does not have a visible record on immigration -- one of the department's flash points -- and Obama renewed his call for overhauling the nation's immigration system as part of his pitch.
"I'm confident that I could not make a better choice in Jeh, somebody who I'm confident is going to be moving not just the agency forward, but helping to move the country forward," he said.
Johnson said he had left government at the end of last year and was settling back into private law practice, but that when he received the call, he "could not refuse it."
A New Yorker, he said he was in Manhattan on Sept. 11 -- "which happens to be my birthday," when it was "shattered by the largest terrorist attack on our homeland in history.
"I wandered the streets of New York that day and wondered and asked, what can I do?" he said. "Since then, I have tried to devote myself to answering that question."