The government of Mali is “hesitant” over the deployment of a UN peacekeeping force, a senior UN official has said.
“We do not have a clear green light from the government of Mali yet for a peacekeeping operation,” said Deputy Secretary-General Jan Eliasson.
However, he said other countries were increasingly in favour of that option.
Thousands of troops from France and African nations have been sent to Mali to oust Islamist militants.
They have recaptured the major towns in northern Mali, which had been under Islamist control since April 2012.
Most of the urban areas were taken without a fight, with the militants said to have fled into mountainous areas of the Sahara Desert near the Algerian border.
But on Sunday, there was four hours of fighting in the region’s biggest town, Gao.
The town is now said to be calm but the BBC’s Thomas Fessy in Gao says there are fears some fighters could be hiding among the population.
The city’s main market remained closed on Monday, following the violence.
Two checkpoints in Gao were hit by suicide bomb attacks on Friday and Saturday.
The Movement for Oneness and Jihad in West Africa (Mujao) has claimed responsibility for the weekend’s violence.
On Saturday, Mujao spokesman Abou Walid Sahraoui said: “We are dedicating ourselves to carrying out more attacks against France and its allies.”
Mr Eliasson said UN peacekeepers would only be deployed after the “combat phase” of the operation was over.
Despite Mali’s “hesitation”, he said he thought “the trend is very much in the direction that we should move into that [peacekeeping] phase”.
After sending some 4,000 soldiers to Mali, France has said it wants to start withdrawing them in March.
Several thousand troops from Mali’s neighbours, including Chad, Niger, Nigeria, Togo and Senegal have already been sent to Mali to retain control of the retaken northern towns and also to take care of security in the south.
If the UN Security Council agreed to deploy a force, these troops would form the bulk of it.
Mali’s army is in disarray after staging a coup in March 2012.
An alliance of Tuareg separatist and Islamist rebel groups took advantage to extend their control over the whole of northern Mali – an area larger than France.