US Deputy Secretary of State William Burns has arrived in Tripoli.
Libyan Prime Minister, Mustafa Abu Shagour aplogised to Burns, in a meeting with him, for an attack on the US consulate in Benghazi in which American ambassador Christopher Stevens died.
Both countries are concerned about the security situation in Benghazi after last week's attack on the US consulate.
Al Jazeera's Hoda Abdel Hamid reports from Benghazi.