The embassy announced William Roebuck arrived in Tripoli to continue the work of Laurence Pope, who served in that capacity since October. Pope took up the position following Sept. 11, 2012, attacks on the U.S. consulate in Benghazi left U.S. Ambassador to Libya Chris Stevens and three members of his staff dead.
"Mr. Roebuck looks forward to working with the Libyan government and the Libyan people as we continue to build the relationship between our two countries during this historic time," an embassy statement read.
U.S. congressional leaders blamed the U.S. State Department for security lapses in the run-up to the September attack.
The Benghazi attack was initially attributed by the Obama administration to anti-American violence surrounding a controversial film denigrating Islam but subsequent investigations determined the film had no part in inciting the Libyan violence.