French President Emmanuel Macron on Wednesday meets Libyan Prime Minister Fayez al-Sarraj, who has accused Paris of supporting his rival and tacitly backing his assault on Tripoli, a presidential source said.

Relations between the two leaders have soured since strongman Khalifa Haftar launched a campaign last month against Sarraj and his internationally recognised Government of National Accord.

Sarraj claimed France had switched sides to support a "dictator", in comments deemed "unacceptable and unfounded" by the presidential source on Tuesday.

"France supports Prime Minister Sarraj and was opposed to Haftar's military offensive against Tripoli," the source said, while reiterating that France had maintained contacts with actors on both sides of the conflict.

On April 4, Haftar launched a drive towards Tripoli where Sarraj's UN-recognised government is based, triggering fighting that has claimed nearly 400 lives.

Macron intends to ask Sarraj about the humanitarian situation and see if he has proposals to end the conflict, which appears to have reached a stalemate in recent days.

"Sarraj is a pragmatic politician whom we can work with," the source said.

"But in his entourage and among his supporters there are some extremists, clans and factions which think it's easier to accuse foreigners, in this case the countries which have been the most active, like France."

On Tuesday, Sarraj met in Rome with Italian Prime Minister Giuseppe Conte, who appeared to rule out any military intervention in Libya.

He was later to meet German Chancellor Angela Merkel, and may travel to London as part of his tour to drum up European support for his beleaguered government.

The French government "has coordinated closely" with officials in Rome, Berlin and London in order to ensure a consistent message on Libya, the presidential source said.

Britain has pushed for a resolution at the UN Security Council demanding a ceasefire in Libya, but its efforts have foundered against opposition from Russia and the United States.