institutions and promised broad consultation on a political transition in a bid to solve the "multi-dimensional crisis" facing the country.
Earlier, residents of the fabled city synonymous with remoteness told AFP they heard heavy weaponry blasting Timbuktu's military base, but the army appeared to have deserted the encampment.
"We can currently hear heavy weapons being fired at the empty military base in Timbuktu," a nurse told AFP by phone. At least one other resident provided similar testimony.
Witnesses said some Malian troops had abandoned their posts and dumped their uniforms. Arab militiamen opposing the rebels, however, appeared ready to defend the city and took up defensive positions.
Timbuktu is the last major town in Mali's north not to have fallen into the hands of Tuareg rebels and Islamist fighters. The town of about 50,000 residents is a United Nation's world heritage site, nicknamed the "pearl of the desert".
Mali's political situation is growing increasingly chaotic after the March 22 coup by disgruntled soldiers in the capital Bamako.
Coup leaders said they seized power because the government had not done enough to stem the Tuareg rebellion, rekindled in January.
Sanogo has said the army would no longer resist rebels in Gao, about 200 miles west of Timbuktu, where rebels seized control Saturday.
"Mali forces have decided not to prolong the fighting" around Gao because of the civilian population, Sanogo said. "A more viable security plan will be put in place so that the whole territory of Mali will not be violated."
It is possible troops in Timbuktu took the same tack and abandoned the town.
Gao, which served as army headquarters for the entire northern region, has fallen to the rebels, an aide to the regional governor told AFP by telephone.
Tuareg rebels confirmed they had taken control of Gao and said they had also surrounded Timbuktu.
"The (Tuareg) MNLA (Azawad National Liberation Movement) has just ended Mali's occupation of the region of Gao by seizing and taking control of (Gao) this Saturday," it said in a statement posted on its website.
MNLA forces were "encircling the city of Timbuktu to dislodge Mali's remaining political and military administration," the statement read.
Gao was rocked by heavy gunfire Saturday, though it was not known how many people were killed or injured in the fighting.
The MNLA has relaunched a decades-old fight for the independence of what the Tuareg consider their homeland in the vast desert region.
It has been joined by the Islamist Ansar Dine (Defenders of Faith, in Arabic) which is headed by renowned Tuareg rebel Iyad Ag Ghaly and has ties to Al-Qaeda's north Africa branch, known as Al-Qaeda in the Islamic Maghreb.
The MNLA's capabilities were boosted when fighters brought weapons into Mali from neighbouring Libya after the fall of Moamer Kadhafi.
The assault on Gao came less than 24 hours after the strategic town of Kidal, to the north, fell into rebel hands following an attack reportedly led by the MNLA and another Islamist group.
With Mali threatening to unravel, the chairman of the Economic Community of West African States (ECOWAS), Ivory Coast's President Alassane Ouattara, said the regional bloc had put 2,000 troops "on alert", ready to intervene if necessary.
Following the coup, the European Union, the United States and other Western powers suspended hundreds of millions of dollars of support for landlocked Mali -- except for emergency aid to drought-hit regions.
Washington, which has warned the region was becoming a new hub for Al-Qaeda, on Friday supported ECOWAS's efforts to force the junta to step down, but said it was concerned with the latest rebel advances.
The Tuareg offensive has caused more than 200,000 people to flee their homes in the remote region that is also a hub for arms and drug trafficking.