The UN said on Saturday it was worried its drawdown could be hampered by an escalation of fighting in the north -- where rival armed groups are seeking to seize territory as the UN pulls out -- and by an influx of Malian troops there.

The UN also said the ruling junta had not given it permits to send in convoys to retrieve its equipment from its bases there.

The departure of the UN peacekeeping mission MINUSMA by the end of 2023 is part of a ongoing security reconfiguration launched by the military junta, which seized power in 2020.

Russian mercenaries and Malian soldiers have begun arriving in the north, local officials told AFP, to replace UN soldiers who the junta has ordered to leave.

"Everything must be done to ensure the work of MINUSMA is ended by December 31," Diop said in a video posted on social media on Saturday evening.

"The government does not forsee any extension of this deadline," he said in the recording of comments he made to a meeting of the diplomatic corps in the capital, Bamako.

There has been an escalation in fighting in the north between majority-Tuareg separatist groups and the Malian army.

The jihadist Support Group for Islam and Muslims (GSIM), which is affiliated to Al-Qaeda, has also stepped up attacks on Malian army posts.

There are fears that violence could escalate with the departure of UN peacekeepers from their camps in Tessalit, Aguelhok and the separatists bastion of Kidal.

The separatists are opposed to MINUSMA handing over its bases to the Malian military.

Diop said he was aware the UN had requested authorisation to send in logistics convoys by road to remove equipment from its northern bases and conduct air operations to protect the drawdown.

"We are working to find solutions," he said.