West Africa's top regional decision-making body urged member states on Monday to back Mali with military equipment and logistics in its fight against northern rebels, but also said it would launch mediation efforts within days.
Fighting erupted in Mali's north in mid-January after heavily armed fighters from Libya last year poured into the remote desert zone, where complaints of marginalisation and insecurity have long simmered.
The current uprising, led by Tuareg fighters, is the most heavily armed yet and comes as the region is grappling with the growing threat of fighters linked to al Qaeda and a food crisis threatening millions with hunger.
Nearly 200,000 people have been displaced by fighting.
"The Commission urges member states and partners to support the government of Mali with logistics and materiel as the country battles to defend its territorial integrity and restore law and order," the 15-nation ECOWAS said in a statement.
The ECOWAS Commission called on MNLA to observe a ceasefire and warned that ECOWAS would take "all necessary measures" to help Mali protect itself, without giving any further details.
The ECOWAS statement said it would also launch a mediation process "in the coming days". Separately the pan-continental African Union's top peace body is due to meet in Bamako on Tuesday to discuss the crisis in the Sahel band.
The MNLA rebels - a combination of veterans from Libya's conflict, rebels from previous Malian uprisings and a younger generation of Tuareg activists - have called for the creation of an independent state in Mali's north.
Underscoring the complexity of Mali's crisis, Ansar Eddine, one of the groups fighting alongside the MNLA, issued a statement saying that it was not fighting for independence, but to apply sharia law in the country's north.
"We do not want a separate republic but an Islamic republic, the Muslim republic Mali," it said.
The group, which has fought alongside the MNLA but is not part of it, is led by Iyad Ag Ghaly, a leader of previous Tuareg rebellions who has also served as a diplomat and acted as a go-between in hostage negotiations for kidnapped Westerners.
Analysts warn that the combination of the MNLA and Ag Ghaly's men, and the presence of fighters linked to al Qaeda, who also operate in the zone, are likely to complicate any effort to resolve Mali's conflict.
The conflict is also threatening to disrupt Mali's planned April 29 presidential election, after which President Amadou Toumani Toure is due to step down.
Hundreds of people demonstrated in the military barracks town of Kati, just north of Bamako on Monday, complaining about the poor conditions of those fighting in the army.
Witnesses said there was also a protest in the northern town of Gao over the weekend as hundreds of residents demanded the government focus on ensuring security before trying to hold an election.