WASHINGTON — The United States said on Tuesday it had captured a suspected ringleader of the 2012 attack on the U.S. diplomatic compound in Benghazi, Libya that killed four Americans, including the U.S. ambassador, and ignited a political firestorm in Washington.

President Obama said in a statement he had authorized the operation in Libya on Sunday, in which U.S. special operations forces captured Ahmed Abu Khatallah. He told an audience later in Pittsburgh that Khatallah was being transported to the United States.

“Since the deadly attacks on our facilities in Benghazi, I have made it a priority to find and bring to justice those responsible for the deaths of four brave Americans,” he said in a statement. He said Khatallah would “face the full weight of the American justice system.”

Khatallah’s capture was a victory for Obama, who has been accused by republicans of playing down the role of al Qaeda in the 2012 attacks for political reasons and being slow to deliver on promises of justice.

Republicans also said then-Secretary of State Hillary Clinton had failed to take steps to ensure the safety of American diplomatic personnel, an issue that is still resonating as Clinton considers running for president in 2016.

Khatallah was being held aboard the USS New York, an amphibious transport dock, a U.S. official said, speaking on condition of anonymity.

He was grabbed on the outskirts of Benghazi in an operation carried out by U.S. special operations forces, including some members of the Army’s Delta Force, another U.S. official said.

General Martin Dempsey, chairman of the Joint Chiefs of Staff, said U.S. troops had acted with “extraordinary skill, courage and precision” and that the complex operation resulted in no casualties. Rear Admiral John Kirby, the Pentagon press secretary, said all U.S. personnel involved had left Libya.

A U.S. official said Khatallah would be charged and prosecuted through the U.S. court system and would not be sent to the prison for suspected al Qaeda militants in Guantanamo Bay, Cuba.

That is in line with Obama’s policy of prosecuting suspected militants caught abroad through the U.S. justice system rather than trying them in the military tribunal system at Guantanamo Bay prison, which he is trying to close.

A criminal complaint released by the U.S. district court for Washington, D.C., accused Khatallah of killing a person in the course of an attack on a federal facility, providing material support to  to terrorists and using a firearm in commission of a crime of violence.