Troops from a regional West African force will be in Mali within days to help a French intervention against Islamist rebels, Nigeria says.
The force's commander, Gen Shehu Abdulkadir, confirmed the move to the BBC as West African military commanders met in Mali's capital, Bamako.
France has almost 800 troops in Mali, and another 1,700 involved elsewhere.
It began its intervention last Friday with the aim of halting the Islamists' advance south.
Nigeria now plans to provide 900 troops for the West African force, 300 more than previously announced.
The force is expected to be 3,300 strong. It will be deployed under UN Security Council resolution 2085, which was passed in December.
Nigerian Col Mohammed Yerima said "the president approved the deployment of a battalion" and added that the first company of almost 200 soldiers would set off by the end of Wednesday.
Nigeria has the biggest military in Ecowas, the regional grouping that is overseeing the military response.
Ivory Coast army chief Gen Soumaila Bakayoko said: "We are here today to speak essentially about the engagement alongside our Malian brothers in arms, to liberate the north of Mali."
Benin, Ghana, Niger, Senegal, Guinea, Burkina Faso and Togo have also pledged troops.
A summit of West African leaders on Saturday is expected to discuss the crisis further, as will a meeting of EU foreign ministers in Brussels on Thursday.
French warplanes have carried out a series of air strikes on Islamist positions since the intervention began on Friday.
The raids continued overnight, with President Francois Hollande saying they had "achieved their goal".
He told a news conference in Dubai on Tuesday that France had three aims in Mali: "to stop the terrorist aggression... making Bamako safe... and enabling Mali to recover its territorial integrity.
"You ask what we'll do with the terrorists that are found - destroy them, take them prisoner if possible."
A convoy of French armoured trucks crossed into Mali from Ivory Coast late on Monday and defence sources told French media that the size of the French force would build up gradually to 2,500.
Quoting diplomatic and military sources, BBC West Africa correspondent Thomas Fessy said French troops would take part in the second phase of the Mali operation, namely driving Islamists out of the main towns they occupied.
Most of the regional armies, apart from Niger, have no experience of the complex task to be carried out in sandy or mountainous conditions, he says.
Raids on Diabaly
Islamists are reported to have pulled out of Gao and the historic town of Timbuktu, two of the big population centres that they overran in the north last year.
One resident in Timbuktu said the population was "free". "We can go out, we can smoke, people are happy," he told BBC Focus on Africa but added that people were too scared to go out on the streets and openly celebrate.
While most Malians are Muslims, the majority belong to the Sufi sect, not the strict Wahhabi interpretation of Islam followed by the Ansar Dine and Mujao rebel groups.
In Gao, one witness told RFI radio "the population is beginning to live normally without fearing the imposition of Sharia".
An Ansar Dine rebel spokesman told a Mauritanian website they had made a "tactical withdrawal".
And Malian journalist Kodji Siby told the BBC that fighting was reported around Timbuktu, a Unesco world heritage site. Fifty rebels were still visible in the centre of the town, one resident said, although the majority had abandoned their posts.
The Islamists struck back on Monday by taking Diabaly, 400km (250 miles) north-east of Bamako.
Major air strikes were carried out overnight to try to dislodge them.
At least 11 Malian soldiers and a French helicopter pilot have died in Mali since Friday's intervention by France. More than 100 militants are reported to have been killed.
Islamist groups and secular Tuareg rebels took advantage of chaos following a military coup to seize northern Mali in April 2012. But the Islamists soon took control of the region's major towns, sidelining the Tuaregs.
The UN says some 144,500 Malian refugees have been registered in neighbouring countries since April 2012.
It also says that 30,000 people have been displaced as a direct result of conflict this month.
France's intervention has prompted concerns for the welfare of eight French hostages kidnapped in the area over the past two years.
President Hollande said on Tuesday that "those who have taken them captive should reflect. There's still time to return them to their families".