UNITED NATIONS: Libya has seen "no reduction of foreign fighters or of their activities" in the centre of the country, says UN Secretary-General Antonio Guterres in a report submitted this week to the Security Council.

"While the ceasefire agreement continued to hold, UNSMIL (the UN mission in Libya) received reports of fortifications and defensive positions being set up along the Sirte-Jufra axis in central Libya, as well as of the continued presence of foreign elements and assets," the document, seen by AFP on Friday, says.

"Despite the commitments made by the parties, air cargo activities reportedly continued with flights to various military airbases in Libya's western and eastern regions," it says.

According to diplomats at the UN, the number of foreign military and mercenaries in Libya is estimated at more than 20,000, including 13,000 Syrians and 11,000 Sudanese, as well as several hundred Turks and Russians. "I reiterate my call on member states and Libyan national actors to put an end to violations of the arms embargo and to facilitate the withdrawal (of) foreign fighters and mercenaries from the country," the UN chief says in the report.

"These are critical elements for lasting peace and stability in Libya and the region," he argues, saying that "progress needs to be continued on the political, security and economic tracks, to enable the holding of national elections" on December 24, 2021.

Libya has been ravaged by bloodshed since the fall and killing of dictator Muammar Qadhafi in a NATO-backed 2011 revolt.

In October 2020 rival groups signed a truce, setting in motion a UN-led process that saw a new transitional government installed.