The militants, some of whom were members of al Qaida in the Islamic Maghreb, imposed a rigid interpretation of Islamic law that allowed for amputations and stonings for some perceived crimes. They also destroyed historically significant shrines in the city of Timbuktu that they considered idolatrous.

U.S. officials remained uncertain whether the al Qaida group was a threat to American interests, but the deaths in September of the U.S. ambassador to Libya and three other Americans deepened concerns. The Libyan government claimed that Mali-based extremists had participated in the attacks on U.S. outposts in Benghazi, and U.S. officials said that some of the alleged attackers phoned fellow extremists in Mali to boast.

The rapid escalation of the conflict this week came as a surprise, however. A military campaign to dislodge the Islamists was being planned by Western nations and Mali’s fellow members of the Economic Community of West Africa wasn’t expected to begin for months, as officials wrestled with how to finance, train and equip the 3,000-man force.

“We’re very happy with France’s decision,” said Ibrahim Garango, part of a pro-government militia positioned in Mopti. Garango, who was reached by phone, said he hasn’t seen any French forces yet and doesn’t know the size of their contingent, but he stressed that any assistance was welcomed.

“These are terrorists and it would’ve been very, very difficult to win against them without help from France,” he said.

U.S. law prohibits direct aid to Mali’s government or military because there have been no new elections since a military coup overthrew the democratic government last year. But U.S. officials said U.S. military assistance could be directed through other international partners, such as the French or the African Union.

“We are monitoring the situation closely," said Department of Defense spokesman Maj. Robert Firman. "We have noted that the government of Mali has asked for support, and we share the French goal of denying terrorists a safe haven in the region."

State Department spokeswoman Victoria Nuland told reporters that the United States is consulting "very closely" with France but that neither Mali nor France has requested direct U.S. military support.

Allam reported from Washington, Boswell from Nairobi, Kenya. McClatchy special correspondent Brahima Ouologuem contributed from Bamako, Mali.