France's President Francois Hollande delivers a speech on the situation in Mali in Paris on Jan. 11, 2013. French forces began backing Malian soldiers Friday in their fight against radical Islamists who are moving toward Bamako. (Issouf Sanogo/AFP/Getty Images)

French ground forces intervened Friday to help the sagging Malian army as it battles advancing Islamist fighters, opening a new and unexpectedly direct front in the confrontation between the West and al-Qaeda-allied guerrillas.

On Saturday, France’s defense minister said hundreds of French troops were involved in an operation that destroyed a command center of Islamic rebels in Mali overnight. Defense Minister Jean-Yves Le Drian said that a French helicopter pilot died of his wounds in the operation, which involved air strikes on three rebel targets, according to the Associated Press.

French President Francois Hollande, who announced the surprise deployment, did not say how many French soldiers were on the ground or exactly what their mission is. But officials said French aircraft conducted strikes Friday, and Hollande promised that France’s participation in the fighting would “last as long as necessary” to guarantee that Mali’s government and army can maintain control of the former French colony in northwest Africa.

“At stake is the very existence of the Malian state,” he said in a televised declaration.

Hollande’s decision to intervene dramatized European and U.S. concerns over rapid military gains in recent days by the half-dozen Islamist and Tuareg militias that have controlled the northern two-thirds of the country for more than seven months. Ruling more than 250,000 square miles, they have scattered Malian soldiers southward, imposed strict Muslim laws on the civilian population and created a vast new haven for North African terrorist groups such as al-Qaeda in the Islamic Maghreb (AQIM).

The slide into political chaos in northern Mali concerns the West for several reasons, including the possible spillover of militancy and weapons to neighboring nations and the relative ease with which West Africa-based militants might attack Europe.

Still, the United States has been leery of rapid international intervention, preferring a slower approach that coordinates military help with economic and political support.

France’s decision to send ground troops, even if they are restricted to small groups of specialized forces, marks a departure from Western powers’ efforts in recent years to avoid direct involvement on the ground in foreign conflicts, after scarring experiences in Iraq and Afghanistan. The West’s heavy participation in the 2011 campaign to overthrow Libyan leader Moammar Gaddafi, for instance, was limited to air power.

The United States has joined with France and other European governments in seeking to organize an African military intervention force to restore Malian government authority. But a senior French security official acknowledged recently that the African force is nowhere near to being ready, meaning that France had to intervene on its own if it wanted to respond to the immediate crisis.

“The terrorists have regrouped in recent days along the line that artificially separates Mali’s north and south,” Hollande said in an earlier talk Friday to assembled French diplomats. “They have even advanced. And they are seeking to deal a fatal blow to the very existence of Mali. France, as is the case with its African partners and all the international community, cannot accept this.”

Hollande, who took office in May, had consistently ruled out the dispatch of French ground forces in Africa, insisting that the days of France operating as an African police force are over. But an appeal Thursday from Mali’s interim president, Dioncounda Traore, and the swift deterioration of the military situation apparently changed his mind.

Mali has not asked for the same kind of emergency help from the United States, a U.S. spokeswoman said Friday. It remained unclear whether the unfolding events would hasten any U.S. role in the country. “The Malian government’s need is urgent right now, which is why France is responding,” State Department spokeswoman Victoria Nuland said.

Hollande indicated that France’s role as a power in Africa that can be relied on seemed to be at stake in Mali. “The terrorists must know that France will always be there to support a population that lives in democracy,” he declared.

France has fighter aircraft, transport planes and helicopter gunships stationed in several African countries near Mali, making air support for the Malian army relatively easy to organize. Foreign Minister Laurent Fabius said Friday that some of the aircraft had carried out strikes against the rebels, and French news reports quoted Malian soldiers as saying they were transported to northern Mali in aircraft made available by “foreign friends.”

Conflicting reports

There were conflicting reports from Mali, just south of Algeria, about an army counteroffensive against Islamist guerrillas who recently captured the city of Konna. “We have chased the army out of the town of Konna,” Sanda Abou Mohamed, a spokesman for the Ansar Dine militia, told the Associated Press by telephone from the Islamist-held city of Timbuktu. But others reported late Friday that Mali’s forces had retaken the city.

Konna lies about 45 miles north of Mopti, the northernmost headquarters for Malian government military operations. French officials expressed fear that the Islamist forces, if they continue their advance, could capture Mopti and from there push forward to Bamako, the capital, more than 300 miles to the southwest.

“Their objective obviously was the control of all Mali in order to turn it into a terrorist state,” Fabius said.

Against that background, France on Friday ordered its nonessential citizens to leave the country, and international aid organizations in Bamako began evacuating their foreign employees. Traore declared a state of emergency late Friday in a speech on national television, the Associated Press reported.

French Defense Minister Jean-Yves Le Drian called the Pentagon to advise Defense Secretary Leon E. Panetta of the military intervention, according to U.S. officials, who said they were reviewing whether Washington could provide intelligence support.

The U.S. military has conducted surveillance over Mali for years with satellites, high-altitude Global Hawk drones based in Europe and small PC-12 turboprops based in Burkina Faso, on Mali’s southern border. Flying armed Reaper or Predator drones over Mali is not an immediate option, however; the Pentagon lacks a base in the region for those aircraft.

The Malian army has been largely in disarray since a bungled coup d’etat in March. After the coup, Tuareg guerrilla forces in the Azawad National Liberation Movement, led by Col. Mohamed Ag Najim, took control of the area with little opposition from the leaderless army. On April 6, they declared independence for “the Islamic State of Azawad,” the Tuareg name for the region.

Northern Mali’s Tuareg population, ethnically different from the black residents of Bamako and the south, have long sought independence or at least greater autonomy. A number of accords have been reached over the years, some brokered by neighboring Algeria, only to end up dead letter.

Najim’s forces were fresh from years of serving in Libya as an adjunct to Gaddafi’s army. As a result, they were trained and well-armed, according to some reports, with surface-to-air missiles from Gaddafi’s arsenal.

In addition, Najim was aided by the Ansar al-Din al-Salafiya, a fundamentalist Islamist Tuareg group with close ties to al-Qaeda in the Islamic Maghreb and led by Iyad Ag Ghali. Before the summer was over, the three main branches of AQIM had filed into the region, along with other extremist groups, and pushed Najim’s mainly secular forces aside, setting up what amounted to an Islamist outland.

Intervention force delayed

With France in the lead, Western nations backed by a U.N. Security Council resolution vowed to set up a 3,300-strong intervention force with soldiers from the Economic Community of West African States (ECOWAS). They were to be trained by French and other European officers, French officials said, and the United States would contribute heavy air-transport planes and intelligence from satellites and drones.

In addition, a team of about 400 European Union officers was scheduled to arrive in Bamako late this month to train 3,000 Malian soldiers in the hope that they could be redeployed in northern Mali, the officials said. American soldiers have been barred under U.S. law from training Malian forces because of the March coup d’etat.

However, the senior official, speaking on the condition of anonymity to address sensitive information, acknowledged that ECOWAS governments so far have not made the necessary soldiers available. The original idea that an intervention could be mounted this spring has been discarded, he said, and the question now is whether it can be put together in time for action in the fall.

In his appeal Thursday, Traore sought urgent aid in response to the emergency along the separation line and the threat of an Islamist advance toward Bamako. Meanwhile, the Security Council on Thursday evening urged “rapid deployment” of the African-led force because of “the serious deterioration of the situation on the ground.”

Traore, who was installed after the coup, was expected in Paris next week for talks with Hollande, officials said.

France’s U.N. envoy Gerard Araud defended his government’s decision Friday to intervene in Mali, telling the U.N. Security Council in a letter that the operation was being carried out “within the bounds of international legality” and that it would last “as long as is necessary” to turn back an Islamist insurgency.

In the letter, Araud officially informed the U.N. Security Council Friday night that France had entered the conflict in response to the Malian request. Mali, he wrote, is “facing terrorist elements” from the north that “threaten the territorial integrity of the state, its very existence, and the security of the population. As a consequence, I would like to inform you that French armed forces have delivered…support to the Malian units to battle against those terrorist elements.”

Anne Gearan and Craig Whitlock in Washington and Colum Lynch at the United Nations contributed to this report.