Turkish President Recep Tayyip Erdogan has warned Europe it could face new threats from terrorist organisations if Libya's UN-recognized government in Tripoli were to fall. 

In an article published on Saturday, the eve of a Libya peace conference in Berlin, Erdogan said the EU's failure to adequately support the Government of National Accord (GNA) would be "a betrayal of its own core values, including democracy and human rights."

The GNA led by Fayez al-Sarraj has been under attack since April from strongman Khalifa Haftar's forces, which are based in the east of the country, with fighting killing over 280 civilians and 2,000 fighters.

"Europe will encounter a fresh set of problems and threats if Libya's legitimate government were to fall," Erdogan wrote. 

"Terrorist organisations such as ISIS (ISIL) and Al-Qaeda, which suffered a military defeat in Syria and Iraq, will find a fertile ground to get back on their feet."

In a joint initiative, Turkey and Russia have brokered a ceasefire but Haftar walked away from talks in Moscow this week aimed at finalizing the truce agreement.

Erdogan's government backs Sarraj and the Turkish parliament earlier this month approved the deployment of troops to Libya after the signing of controversial security and maritime deals between Tripoli and Ankara.

"To leave Libya at the mercy of a warlord would be a mistake of historic proportions," he said, in a veiled reference to Haftar.

Erdogan, who is also due to attend the Berlin talks, wrote in Politico that the Libyan civil war served as a "litmus test" for the EU to show whether its leaders would abdicate their responsibilities and watch the crisis unfold from the sidelines. 

"The EU needs to show the world that it is a relevant actor in the international arena," he said. 

World powers are trying to mediate a lasting ceasefire at the international conference in Berlin on Sunday which the warring parties are expected to attend.

"The upcoming peace conference in Berlin is a very significant step toward that goal. European leaders, however, ought to talk a little less and focus on taking concrete steps," said Erdogan.

"We hope what comes out of Berlin is renewed demonstration of international unity in supporting the intra‑Libyan political process, ending foreign interference, leading to full respect of the UN arms embargo," UN spokesperson Stephane Dujarric said at a press briefing on Friday. 

The conference will aim to agree on six points – including a permanent ceasefire, implementation of a much-violated UN arms embargo and a return to political efforts for peace. 

An interim truce that came into force in Libya last Sunday has mostly held, despite accusations of violations from Haftar's forces and the rival GNA.

The fighting has spurred a growing exodus of migrants and refugees, many embarking on rickety boats from Libya towards Europe.

Haftar is backed by the United Arab Emirates, Egypt, and Jordan, as well as Sudanese and Chadian fighters, and most recently Russian mercenaries. France has also given him some support.

On the other side, Turkey has supported Serraj by sending troops to balance out recent gains by Russian snipers. Hundreds of pro-Turkey fighters from Syria's war have also been deployed, diplomats say.

(With input from Reuters and AFP)