African forces on Wednesday began moving toward Mali's center to replace the French mission as the French troops have continued to push north in their bid to flush out al Qaida-linked rebels who have threatened reprisal attacks.

More than 150 soldiers from Burkina Faso have arrived in Markala, 270 km north of the capital of Bamako, and have taken over the baton from the French troops.

"The African force is deploying much faster than expected," French Foreign Minister Laurent Fabius said in Paris. "Obviously that poses a number of logistical difficulties but I have to say that I have seen a very big effort by our African friends."

The 15-nation West African bloc ECOWAS is mobilizing 3,300 soldiers for an Africa-led mission in Mali after the UN Security Council approved its deployment plan in December 2012.

Chad, which is not a member of ECOWAS, has also pledged to contribute to the Africa-led mission in Mali to restore its territorial integrity.

In Washington, U.S. Secretary of State Hillary Clinton said on Wednesday that the United States will not let northern Mali become a safe haven for terrorists and extremists.

Appearing at the Senate Committee on Foreign Relations to testify about the deadly Sept. 11 attack on the U.S. consulate in Benghazi, Libya, the top American diplomat called the presence in northern Mali of extremists and al Qaida-affiliated militants "a very serious, ongoing threat."

"We are in for a struggle, but it is a necessary struggle," Clinton told senators. "We cannot permit northern Mali to become a safe haven."

The U.S. military has begun airlifting French troops and equipment into Mali to assist their operation against the rebels who are running northern Mali and trying to push southward, as Washington has been coordinating efforts to engage African nations in the operation and restore a civilian government in the West African nation following a coup in March last year.

The Obama administration sent some 100 military trainers last week to Niger, Nigeria, Burkina Faso, Senegal, Togo and Ghana, nations that are poised to send troops to Mali.

The Malian government on Monday announced to extend the nationwide state of emergency for three months.

The authorities said that the good progress of the ongoing military operations to liberate the occupied regions in the North and the need to maintain social order across the national territory justifies the extension of the state of emergency.

On Jan. 11, the Malian government declared a state of emergency across the country for a period of 10 days.