The UN chief said in a new report that African troops forming the core of a UN peacekeeping mission deploying in Mali next month are not yet properly equipped.
France launched a massive military campaign in January which broke al-Qaeda-linked Islamist fighters' control over the northern two-thirds of Mali and allowed the Tuaregs to regain control of their traditional fiefdom of Kidal.
But UN Secretary-General Ban Ki-moon said in a report to the Security Council on Saturday that despite the gains made by French troops, Malian security forces and an African force known as Afisma, the situation continues to be precarious.
"The situation on the ground remains … fluid, with sporadic clashes between armed groups and continued asymmetric attacks across the three regions of the north," Ban said in the report, obtained by Reuters.
"Furthermore the advance of the MDSF [Malian defence and security forces] northwards towards Kidal and the fatal clashes with MNLA [separatist Tuareg] elements on 5 June have exacerbated tensions and increased the volatility of the situation in the region," it said.
To reduce those renewed tensions, Mali's government and Tuareg separatists began talks on Saturday that both sides said they hoped would lead to a ceasefire ahead of national elections next month and pave the way for a permanent peace deal.
The talks in the capital of neighbouring Burkina Faso, due to conclude on Monday, follow the first fighting in months between Mali's army and the MNLA rebels this week as government forces advanced toward the Tuaregs' last stronghold of Kidal in the remote north-east.
Once the UN peacekeeping force, to be known as Minusma, is deployed, France will continue to handle counterterrorism and peace enforcement operations in Mali, while the UN blue helmets will handle traditional peacekeeping duties of policing and trying to ensure new violence does not erupt.
In April, the UN Security Council unanimously approved a mandate for the 12 600-strong Minusma peacekeeping force from July 1. The force will be supported by French troops if needed to combat Islamist extremist threats.
Deployment of the force will be subject to a council review of security in Mali in late June.
Ban said the African troops expected to be moved under UN command next month must still be brought up to UN standards in terms of their equipment and ability to sustain themselves in the landlocked West African country.
"Deployed Afisma units have been given a grace period of four months to reach the required United Nations standards," the report said. "Critical gaps remain for attack and utility helicopters as well as for information units."
He said the UN force could face serious risks on the ground.
"While the operational capabilities of the armed groups have been reduced, attacks in recent months in Mali and the sub-region have shown that they retain the capability to pose a significant threat," Ban said.
"The Malian [security forces] and Afisma have been targeted. United Nations troops and other United Nations personnel may well face a similar risk."
Ban also said the situation in Mali posed risks to neighbouring countries because of the "danger of armed elements moving to neighbouring countries to carry out terrorist attacks and engage in criminal activities".
There are other problems. Ban said the UN has received allegations of serious human rights violations in northern Mali by both the Malian troops and armed groups, including summary executions, arbitrary arrests, enforced disappearances, and destruction and looting of private property.
"The human rights situation in Mali remains of grave concern," the report said.
It said there had also been grave violations against children, including recruitment and use of children as soldiers, sexual violence, killings, maiming and attacks on schools and hospitals.
The report said reports of retaliatory violence by Malian troops against members of the Tuareg and Arab communities have decreased.
"However, in Timbuktu, the risk to these communities remained significant in light of persistent perceptions of their association with armed extremist groups," it said.
"Most members of the Arab and Tuareg communities in the Timbuktu regions have not returned, fearing retaliation by the MDSF and the local population." – Reuters