The European Union's top diplomat has urged all conflict parties in Libya to immediately stop all military operations and engage constructively in peace negotiations.
As Turkish drones helped drive eastern Libyan forces back from Tripoli this month, Russia was said to be reinforcing the forces with warplanes, raising the stakes in a stalemated civil war that has partitioned the African country.
Recent weeks have marked a turning point in a complex conflict between two uneasy coalitions that are each backed by an array of foreign states whose competing regional agendas make them unwilling to countenance defeat.
In a joint statement with the foreign ministers of Germany, France and Italy issued on Tuesday, the EU's top diplomat, Josep Borrell, called on the conflict parties in Libya to swiftly agree on a ceasefire and withdraw all foreign forces, mercenaries and military equipment.
The joint statement followed increased diplomatic efforts by Germany to push for a political solution to the Libya crisis.
Chancellor Angela Merkel earlier on Tuesday expressed her concern in a telephone call with Russian President Vladimir Putin over the recent escalation of fighting in Libya.
On Monday, Merkel discussed the situation in conflict-wracked Libya with Egyptian President Abdel Fattah El-Sisi.
Merkel told Sisi that United Nations-backed negotiations must remain the key aim of a peace process in Libya, where the Government of National Accord (GNA) is fighting General Khalifa Haftar's Libyan National Army in the east.
On Saturday, Sisi proposed a new ceasefire after the Turkish-backed GNA won a series of rapid victories over Haftar's forces.
* This story has been edited by Ahram Online