The UN's special envoy for Libya will on Tuesday meet with representatives of the country's rival parliament based in Tripoli, which is not recognised by the international community, the UN said.
The meeting in Istanbul will likely focus on convincing the General National Congress (GNC) to take part in talks due to be held this week in Geneva aimed at ending violence in the north African country.
Libya has two rival parliaments and governments and has been torn apart since the international community helped to oust dictator Moamer Kadhafi in 2011.
The one in Tripoli is controlled by Islamist-backed Libya Dawn forces, and the internationally recognised government operates out of Tobruk, in the far east of the country.
"Bernardino Leon, will hold consultations… with representatives of the General National Congress to discuss ways to move forward the dialogue process with a view to reaching a peaceful solution to the political crisis and military conflict in Libya," a UN statement said.
"The meeting in Istanbul… will discuss GNC concerns with respect to the political agreement and ways to overcome them."
The September 3-4 talks in Geneva are the latest round in long-running peace negotiations between Libya's rival factions.
The United Nations has been brokering talks aimed at establishing a unified government.
The factions agreed in January to set up a unity government to restore the stability shattered since the 2011 revolution, but negotiations on modalities and over posts have run into hurdles.
