In a statement released by the White House, Obama said he had authorised the strike in Libya in which U.S. military troops, working with law enforcement personnel, captured Khatallah on Sunday (local time).
"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," Obama said.
"The fact that (Khatallah) is now in U.S. custody is a testament to the painstaking efforts of our military, law enforcement, and intelligence personnel.
"Because of their courage and professionalism, this individual will now face the full weight of the American justice system," he said.