The United Nations Security Council has "strongly condemned" deadly fighting in northern Mali between government forces and separatists.
At least 36 people were killed in clashes after troops were sent in to respond to Tuareg rebels who attacked government offices in Kidal last week.
The rebels on Monday released over 30 civil servants they had taken hostage during the attack.
The Security Council late Tuesday demanded an "immediate and unconditional withdrawal" of armed groups that still control some government buildings.
It said those responsible should be held accountable, and called for a "credible and inclusive negotiation process" to help bring long-term peace and stability.
Mali has been in turmoil since last year, when a Tuareg rebellion touched off a coup in the capital, Bamako. The chaos led to a brief Islamist militant takeover in the north and prompted French and African troops to intervene.
On Tuesday, Mali Foreign Minister Abdoulaye Diop urged the Security Council to approve a "much more robust mandate" for the U.N. peacekeeping mission, which is soon up for renewal.
The soldiers are currently authorized to keep peace, but are not authorized to undertake offensive military operations. Diop said this is necessary to help soldiers "deal with threats on the ground and disarmament of all armed groups."
Tuareg rebels took control of Kidal earlier this year after French and African forces drove out the Islamist militants. Kidal is the stronghold for the Tuareg rebels who have been fighting for an independent ethnic Tuareg state in northern Mali.