YAOUNDE (AFP) - Five African nations on Saturday pledged to deploy 8,700 troops, police and civilians as part of a regional effort to fight Nigeria's Boko Haram militants.

"The representatives of Benin, Cameroon, Niger, Nigeria and Chad have announced contributions totalling 8,700 military personnel, police and civilians," the countries said in a statement after a meeting in Cameroon's capital Yaounde.

The news emerged from a three-day summit focusing on forging a strategy for battling the militants, who are engaged in a worsening six-year insurgency centred in northeastern Nigeria.

African Union leaders will submit the plan crafted by Western and African experts to the UN Security Council for approval.

Boko Haram's attacks have increasingly spilled over from Nigeria into neighbouring nations.

Their first major attack in Niger on Friday triggered a forceful response from Chadian and Nigerien troops.

Niger's defence minister reported that 109 of the Islamists were killed in the fighting, along with four soldiers and a civilian. Seventeen other troops were wounded.

The United States said it condemned the attack in the "strongest possible terms" and pledged support for regional forces.

"This unchecked killing must stop," State Department spokeswoman Marie Harf said. "We continue to provide support to governments in the region, including through intelligence sharing, and are increasing our support for these efforts."

Chad already has troops fighting Boko Haram on two fronts, with soldiers deployed in Niger and Nigeria.

Nigeria's military has drawn fierce criticism for failing to rein in the insurgents, who have intensified attacks ahead of presidential and parliamentary elections set for Feb 14.

Nigerian election authorities said they will announce on Saturday whether the polls will be delayed as problems mount with distributing identity cards to 68.8 million registered voters.