Russia's acting foreign minister Sergei Lavrov said on Friday that documents for a Libya peace conference were nearly ready but the war-scarred country's rivals refused to speak to each other.
World powers are preparing to hold a peace summit in Berlin this weekend as they step up efforts to find a lasting ceasefire in the north African country.
"In my opinion, final documents look practically ready," Lavrov told reporters.
But he underlined the huge tensions between the heads of Libya's warring sides -- eastern military strongman Khalifa Haftar and the head of Tripoli's UN-recognised government Fayez al-Sarraj.
"So far ties between them are very tense, they don't even want to be in the same room to say nothing of meeting each other," Lavrov said.
Earlier this week, two men attended talks in Moscow but Haftar abruptly left on Tuesday without signing a permanent truce to end nine months of fighting.
Lavrov said it was important for both sides not to "repeat past mistakes" and put forward additional demands after the Berlin conference.
The oil-rich North African state has been in turmoil since dictator Moamer Kadhafi was killed in the 2011 NATO-backed uprising and multiple foreign powers have become embroiled.
Last April, an assault on Tripoli by Haftar's forces sparked fighting that has killed more than 280 civilians and 2,000 fighters, displacing thousands.