France is planning to deploy a total of 2,500 troops in Mali, more than three times the number sent so far to its former colony, defence sources said.
The revelation on Tuesday suggests the government is ready to commit to a far bigger, and inevitably far longer, role in the campaign against al-Qaeda linked groups in northern Mali than previously indicated.
President Francois Hollande said earlier on Tuesday that there were currently 750 French soldiers in the former colony but acknowledged that this figure would increase.
"There will be a gradual build-up to a figure of 2,500," a source close to Defence Minister Jean-Yves Le Drian said.
The plans to deploy a force of that size is at odds with suggestions by government ministers that the involvement of French ground troops would be limited to protecting Mali's capital, Bamako.
According to Le Monde and other French media, France is also planning to base a substantial contingent of troops at Mopti in central Mali, from where they will be able to carry out operations in the north of the country.
Until now, ministers have portrayed France's involvement as restricted to stopping the rebels' push south with the subsequent task of regaining control of the north to be handed over to the Malian army with the support of troops from neighbouring West African states.
Military analysts have described this scenario as optimistic given the limited capacity of the Malian army and the West African forces lack of experience in combating battle-hardened, well-armed guerrilla fighters in unfamiliar desert terrain.
Foreign Minister Laurent Fabius said on Sunday that he thought involvement in the Mali campaign would essentially be aerial and claimed France's mission could be completed in a matter of weeks.
French assault on Diabaly
Meanwhile, French forces have assaulted the besieged town of Diabaly in central Mali, after an earlier rebel counter-offensive took the town, residents say.
The French bombing campaign, which continued through Monday night, came after the French ambassador to the United Nations said that his country launched the military intervention in the West African country because it believed that "the existence of Mali" was at stake.
Gerard Araud told a closed-door meeting of the UN Security Council that France was responding to calls for help from the government of the former French colony.
A meeting of the 15-nation UN Security Council on Mali expressed unanimous "understanding and support" for the military intervention, Araud said late on Monday.
Francois Heisbourg, special adviser at the Foundation for Strategic Research based in Paris, told Al Jazeera:"Either one of two things will happen; the Malian government, with ECOWAS and the French, will try to use the opportunity to go north, but if they do this they have to do it before the next 6 weeks and the rainy season, or they will have to wait until autumn. I think they are more likely to do the former.
"Also Algeria has closed the border from the north, preventing the rebels from moving that way," therefore working in favour of an advancement by the French on the north.
'They will never leave'
A commander of the Movement for Oneness and Jihad in West Africa, one of the extremist groups controlling northern Mali, taunted the French.
He said that his fighters control Diabaly, as well as Konna, the first town bombed by the French last week. He told AP news agency: "I would advise France not to sing their victory song too quickly. They managed to leave Afghanistan. They will never leave Mali."
Hours earlier, rebel fighters had responded to French airstrikes and military action with a counter-offensive in Diabaly, French and Malian authorities confirmed.
Araud said France had "no other choice" but to help the Malian government.
"We will defend [the capital] Bamako. We will not let the southern part of the country, with its 13 million inhabitants, fall to terrorist groups," said Araud.
But the Organisation of Islamic Cooperation, of which Mali is a member, called on Tuesday for an "immediate ceasefire, dubbing the offensive "premature" and urging all parties to return to the negotiating table.
So far the unrest has caused nearly 150,000 people to flee the country, while another 230,000 are internally displaced, the UN humanitarian agency said Tuesday.
The UN High Commissioner for Refugees has registered 144,500 refugees in neighbouring countries; 54,100 in Mauritania, 50,000 in Niger, 38,800 in Burkina Faso and 1,500 in Algeria, OCHA said.