Senior US State Department official Joey Hood held talks in Tripoli on Tuesday in a show of support for Libya's transitional government, and urged the withdrawal of all foreign forces.
"The US opposes all military escalation and all foreign military intervention. We oppose foreign fighters. We oppose proxy forces," the acting assistant secretary for Near Eastern affairs, the highest-ranking US official to visit Tripoli since 2014, told a news conference.
"To this end, we are urging all sides, Libyans and foreign, to fully implement the ceasefire. This includes the removal of all foreign military forces of all types," Hood said.
"The goal of the US is a sovereign, stable and unified Libya with no foreign interference and a state that is capable of combatting terrorism," he said after talks with Prime Minister Abdulhamid Dbeibah and Foreign Minister Najla al-Mangoush.
Oil-rich Libya has been torn by conflict since the toppling and killing of dictator Moamer Kadhafi in 2011.
But in October, rival groups signed a truce, setting in motion a UN-led process that saw a new transitional government installed.
Dbeibah's team is tasked with organising national elections set for December.
"The agreement on an electoral road map for elections in December is very important for national reconciliation," Hood said.
Mangoush hailed the role of US President Joe Biden's administration in efforts to resolve Libya's decade-old crisis and also called for a pull-out of foreign fighters.
UN Secretary-General Antonio Guterres has said Libya has seen "no reduction of foreign fighters or of their activities" in the country.
The number of foreign troops and mercenaries in Libya is estimated at more than 20,000, including 13,000 Syrians and 11,000 Sudanese, as well as several hundred Turks and Russians.