UN Secretary-General Antonio Guterres hailed "tangible progress" made in recent months in tackling Libya's almost decade-long crisis, in a report submitted Monday to the Security Council in which he demanded all foreign troops and mercenaries leave the country by the week's end.

"Tangible progress was achieved in advancing the UNSMIL-facilitated political, security and economic intra-Libyan dialogues over the last few months," said the document, obtained by AFP and referring to the UN mission in Libya.

Guterres said that "sustained international engagement" in UN-facilitated talks "has generated considerable impetus, demonstrated by tangible progress on the political, security, economic and international humanitarian law and human rights tracks, moving Libya forward on the road to peace, stability and development."

Recognizing that the "Libyan economy is at a precipice," the UN head urged all parties in the drawn-out civil war "to maintain their resolve in reaching a lasting political solution to the conflict, resolving economic issues and alleviating the humanitarian situation for the benefit of all Libyan people."

He also urged all "regional and international actors to respect the provisions of the ceasefire agreement" agreed upon on October 23 that set out a withdrawal within three months of all foreign troops and mercenaries from the country.

That deadline for withdrawal falls on Saturday, and the UN estimates there are still some 20,000 foreign forces and mercenaries in Libya helping the warring factions, the UN-backed Government of National Unity in Tripoli and strongman Khalifa Haftar in the east of the country.

Guterres encouraged all parties to implement the terms of the ceasefire "without delay," something he noted "includes ensuring the departure of all foreign fighters and mercenaries from Libya, and the full and unconditional respect of the Security Council arms embargo," which has been in place since the conflict broke out almost a decade ago.

The next meeting of the Security Council on Libya is scheduled for January 28. Britain is preparing a resolution for the UN mission to have a supervisory role and to monitor the departure of foreign forces from Libya to ensure the terms of October agreement are met.