Fighters of Libya's UN-backed Government of National Accord are seen during clashes with the east-based Libyan National Army (LNA) at the Al-Yarmook frontline in Tripoli, Libya, on August 29, 2019. (Photo: Xinhua)

World leaders committed to ending all foreign meddling in Libya's civil war at a Berlin summit on Sunday, and to uphold a weapons embargo as part of a broader plan to end the long-running conflict.

The presidents of Russia, Turkey and France were among global chiefs signing up to the agreement to stop interfering in the war - be it through weapons, troops or financing.

But the talks failed to deliver "serious dialogue" between the warring parties - strongman Khalifa Haftar and the head of Tripoli's UN-recognized government Fayez al-Sarraj - or to get both sides to sign up to a permanent truce.

"Ensuring that a cease-fire is immediately respected is simply not easy to guarantee," said summit host Chancellor Angela Merkel. "But I hope that through today's conference, we have a chance the truce will hold further."

US Secretary of State Mike Pompeo acknowledged that there are "still some questions on how well and effectively" the commitments can be monitored. 

But he said he is "optimistic that there will be less violence and... an opportunity to begin the conversation that [UN special envoy] Ghassan Salame has been trying to get going between the Libyan parties."

Libya has been torn by fighting between rival armed factions since a 2011 NATO-backed uprising killed Muammar Gaddafi. Most recently, Sarraj's troops in Tripoli have been under attack since April from Haftar's forces.

Clashes have killed more than 280 ­civilians and 2,000 fighters and displaced tens of thousands, until a fragile cease-fire backed by both Ankara and Moscow was put in place on January 12.

Although Sarraj's government is recognized by the UN, powerful players have broken away to stand behind Haftar - turning a domestic conflict into what some have described as a proxy war in which international powers jostle to secure their own interests.

Alarm grew in recent weeks after Turkey ordered in troops to shore up Sarraj's Tripoli-based Government of National Accord.

UN chief Antonio Guterres said the world powers had made "a strong commitment to stop" the conflict escalating into a regional confrontation.