Addis Ababa - African leaders have agreed to send 7 500 troops to fight the Boko Haram insurgency in northeast Nigeria, an African Union official said Saturday.

The move came after the council urged heads of state to endorse the deployment of troops from five West African countries to fight the terror group, said the head of the African Union's Peace and Security Council, Samil Chergui.

African leaders who are members of the 54-nation African Union are meeting in the Ethiopian capital Addis Ababa for a two-day summit that ends Saturday.

UN Secretary General Ban Ki-moon earlier said he support the AU's move to send a force to fight Boko Haram. Boko Haram is increasing its attacks as Nigeria prepares for 14 February elections. Thousands have been killed in the 5-year insurgency.

African nations have opened up a new international front in the war on terror. On Thursday, neighbouring Chad sent a war plane and troops that drove the extremists out of a northeastern Nigeria border town in the first such act by foreign troops on Nigerian soil.

Chad's victory, and the need for foreign troops, is an embarrassment to Nigeria's once-mighty military, brought low by corruption and politics. The foreign intervention comes just two weeks before hotly contested national elections in which President Goodluck Jonathan is seeking another term.

Chergui said Chad's operation against Boko Haram was a result of a bilateral arrangement between the Chad and Cameroon.

"It is conducted as part of a bilateral agreement and arrangement between the two countries. The AU, however, will launch the force in the future," he said.