"The message was simple and unambiguous - Gaddafi must leave power so that a new political process can begin that reflects the will and aspirations of the Libyan people," it said.
The US did not give the location of the talks, but Libya said they had taken place on Saturday in neighbouring Tunisia.
Libyan government spokesman Moussa Ibrahim hailed the talks as an important step in "repairing relations" with the US.
"We support any dialogue, any peace initiative as long as they don't decide Libya's future from without," he told journalists in Tripoli.
"We will discuss everything but do not condition your peace talks. Let the Libyans decide their future," he added.
Washington said that Jeffrey Feltman, the US assistant secretary of state for near eastern affairs, and the US ambassador to Libya Gene Cretz, had been involved in the talks, but would not say who represented the Libyan side.