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)

Representatives of the warring parties in Libya meeting in ­Geneva have agreed on the principle of turning their shaky truce into a lasting cease-fire, the UN's Libya envoy said Tuesday.

The agreement came as UN Secretary-General Antonio Guterres denounced as a "scandal" continuing foreign interference in the war-torn country.

"The principle has been adopted from the first session. Now the question is what are the conditions," Ghassan Salame told reporters in Geneva.

Five senior officers appointed by the UN-recognized Government of National Accord (GNA) and five appointed by the Libyan National Army (LNA) of Khalifa Haftar are taking part in the talks.

"We started yesterday to discuss with them... an attempt to transform the truce into a more solid one, less often violated by either side," he said.

The talks are being moderated by Salame, who last week lashed out at what he branded "unscrupulous" foreign players for meddling in the conflict in the North African country.

The talks started on Monday and continued on Tuesday, Salame said. 

"There is a genuine will for both parties to sit together and start negotiating together," he said. "So far we had separate sessions for both parties but I'm sure the time will come for the two sides to sit together."

At a summit in the German capital Berlin last month, world leaders committed to ­ending all foreign interference in Libya and to uphold a weapons embargo to help end the long-­running civil war.

Guterres told reporters in New York that the embargo "remains violated."

"I must say I'm deeply frustrated with what's happening in Libya. I think that what's happening is a scandal," he added.

Salame said the two sides would meet for talks on economic cooperation in Cairo on Sunday and could hold political talks on resolving the conflict in Geneva in two weeks' time.

He also reiterated his calls for the international community to assist with the lifting of an oil blockade imposed by forces loyal to Haftar and to prevent the flow of arms and mercenaries into Libya.

Libya has been mired in chaos since a 2011 NATO-backed uprising that killed longtime leader Muammar Gaddafi, with two rival administrations vying for power.