In this photo provided by the United Nations, Kim Song, the new Permanent Representative of the Democratic People's Republic of Korea, left, shakes hands with United Nations Secretary General António Guterres, after presenting his credentials Thursday, Sept. 20, 2018 at United Nations Headquarters. (Eskinder Debebe/The United Nations via AP)

The UN Secretary General, Antonio Guterres, says his talks with Libya’s most powerful military commander have ended in failure.

“I leave Libya with a heavy heart and deeply concerned,” he tweeted after meeting Khalifa Haftar in the eastern city of Benghazi, in an attempt to prevent what he called a bloody confrontation.

On Thursday, Khalifa Haftar ordered his forces to advance on the capital Tripoli, where the internationally recognised government is based.

Mr Haftar has his powerbase in the east of the country, where he is allied to a rival government.

In his tweet, Mr Guterres repeated the UN’s commitment to facilitating a political solution and supporting the Libyan people.