The EU must not look "weak" in enforcing a UN arms embargo on Libya, the Greek government said Friday after recent naval incidents involving Turkey.

Strongman Khalifa Haftar has backed a ceasefire in Libya starting Monday, Egypt's president announced after talks in Cairo, following a series of military victories by the country's UN-recognised government.

Libya's UN-recognised unity government retook the town of Tarhuna southeast of Tripoli on Friday, depriving eastern-based strongman Khalifa Haftar of his last redoubt in the west, a spokesman said.

"Our heroic forces have extended their control over the whole of Tarhuna," said Mohamad Gnounou, spokesman for the Government National Accord, already buoyed by the recapture of the whole of greater Tripoli.

A year ago, Libyan strongman Khalifa Haftar began his offensive to seize the capital Tripoli from the UN-recognised government, a conflict which has left hundreds dead and over 150,000 displaced.

President Recep Tayyip Erdogan on Tuesday said two Turkish troops have been killed in Libya, a country wracked by conflict between its UN-recognised government and the forces of strongman Khalifa Haftar. 

Libyan eastern commander Khalifa Haftar met Russian Defence Minister Sergei Shoigu on Wednesday for talks on resolving the conflict in the north African state, the Russian defence ministry said in a statement.

Syrian militants affiliated with groups such as al-Qaida and the Islamic State group are currently being sent by Turkey to fight on behalf of the U.N.-supported government in Libya, according to two Libyan militia leaders and a Syrian war monitor.

Both sides in Libya's civil war receive equipment and backing from foreign countries. But Turkey, which has long trained and funded opposition fighters in Syria and relaxed its borders so foreign fighters joined IS, has in recent months been airlifting hundreds of them over to a new theater of war in Libya.

The United Kingdom sent its fellow Security Council members an amended draft resolution on Libya Friday, calling for the withdrawal of mercenaries from the country, according to the text, seen by AFP.

Turkey's President Recep Tayyip Erdogan warned on Friday of chaos in Libya unless peace is quickly established, as he hosted German Chancellor Angela Merkel. 

The Libyan capital's only operational airport has closed again after threats by forces loyal to strongman Khalifa Haftar, dealing another setback to peace efforts as regional foreign ministers prepare to meet in Algeria Thursday.