Oil blockade

The Berlin agreement also sought to address the issue over who controls over Libya's enormous oil reserves, recognising the authority of the Tripoli-based Central Bank of Libya and National Oil Company (NOC), as well as calling for an end to interference with oil facilities.

The shutdown of ports and oilfields will more than halve Libya's crude exports, plummeting from 1.3m barrels per day to just 500,000 and will cost it $55m per day, according to the Tripoli-based National Oil Company, which declared force majeure, meaning it could not honour contracts because of unforeseen events.

"At the end of the day, an oil blockade is a self-defeating gambit as all actors, including Haftar's forces, require oil income to remain afloat," said Eaton.

The events, as well as reports of the ceasefire being breached, will call into question how sincere the rivals are in setting aside arms and engaging with the UN peace process, which was first proposed by Ghassan Salame, chief of the UN's Libya mission, last July.

"Long experience makes us doubt the intentions, seriousness and commitment of the other side, whom everyone knows seeks powers at any price," al-Sarraj told German news agency dpa before the meeting.

Outside the Federal Chancellery in Berlin, where discussions were taking place, pro-Haftar and pro-GNA protesters waved banners denouncing foreign interference in the conflict.

"Erdogan is the leader of terrorist groups," read one sign from supporters of the general, while supporters of the government held another featuring Haftar's face and the caption: "No to the military coup".

Though Haftar's forces have become bogged down in the suburbs of Tripoli for months, continued air attacks and front line fighting since April has seen hundreds of civilians killed and more than 150,000 forced to flee their homes, according to UN children's fund or UNICEF, which also warned that children were being recruited as soldiers.