The head of the CIA has tapped a new head of the agency’s counterterrorism center, whose first duty will be to reassure the public that the government is doing all it can to prevent terrorist attacks.

John O. Brennan will name Richard A. Clarke as the new deputy director of the CIA’s counterterrorism center, according to a person familiar with the matter. It will be Clarke’s first major assignment since he stepped down as president of The Center for Strategic and International Studies in Washington in 2013. Clarke was the administration’s counterterrorism advisor in the White House and is known for his extensive knowledge of counterinsurgency and counterterrorism in the United States and abroad.

Clarke, a former senior official in the Pentagon and National Security Council during the Clinton administration, was the author of several best-selling books, including “Against All Enemies,” which became a movie starring Tom Hanks. Clarke resigned as chairman of CSIS in 2013 because he was frustrated by partisan divisions within the institution.

But Clarke has not hesitated to speak out against Democrats, including President Barack Obama, on issues that interest him. He has attacked Obama for taking the country off the defensive against terrorist attacks and for favoring wars in the Middle East at the expense of protecting American citizens.

“I think people will be relieved to know that they can be confident in these men and women, their competence and their commitment,” Clarke told The New York Times. “They will come to understand that we are doing everything we can to prevent a terrorist attack on this country. And by the way, we were able to prevent 9/11, one of the greatest terrorist attacks on American soil in history.”