The White House said Friday that President Obama would nominate Matthew G. Olsen, general counsel for the National Security Agency and previously a longtime Justice Department official, to be the nation’s next counterterrorism chief.

Michael E. Leiter, the current director of the National Counterterrorism Center, plans to step down next week.

Olsen, 49, has been in his position at the NSA for just over a year. Before leaving the Justice Department, where he worked for 18 years, he directed the interagency Guantanamo Review Task Force, overseeing the Obama administration’s assessment of every detainee at Guantanamo Bay, Cuba, as part of its plan to close the facility.

The task force provided recommendations on whether detainees should be prosecuted, held in prolonged detention without trial, or transferred home or to third countries for resettlement. The effort was seen as a critical prelude to the closure of Guantanamo, a plan that foundered in the face of intense congressional opposition and disagreement within the administration about how to pursue the goal.

Although Guantanamo remained open, those who worked with Olsen — a mixture of military, intelligence and diplomatic officials, as well as federal prosecutors — said there was surprisingly little rancor in the review process, despite the toughness of some of the decisions and the potential for bureaucratic infighting.

“He will be a bulwark of good sense and determination,” said one administration official who worked with Olsen on Guantanamo. The official spoke on the condition of anonymity because he is not authorized to speak about personnel matters.

The Senate must confirm Olsen, a graduate of the University of Virginia and Harvard Law School. He is also an adjunct professor of law at Georgetown University.

“Matt has a distinguished record of service in our intelligence community, and I’m confident he will continue to build on our strong counterterrorism efforts,” Obama said in a statement.

The NCTC, created in 2004, is tasked with sifting through disparate sources of intelligence to uncover terrorism threats. The center was criticized for failing to identify the Nigerian who attempted to bring down a Detroit-bound commercial airliner on Christmas Day 2009. Leiter, in response, instituted reforms to increase the likelihood that analysts would zero in on clues.

Staff researcher Julie Tate contributed to this report.