The African Union has called for a regional five-nation force of 7,500 troops to defeat the "horrendous" rise of the Nigerian armed group Boko Haram, AU Commission Chief Nkosazana Dlamini-Zuma has said.
The statement on Friday came after Boko Haram increased cross border raids in recent weeks, in neighbouring countries such as Cameroon and Chad, as it continued to take over more territory in Nigeria.
"Boko Haram's horrendous abuses, unspeakable cruelty, total disregard for human lives, and wanton destruction of property are unmatched," Dlamini-Zuma said in a statement after the bloc's Peace and Security Council met late Thursday, ahead of a full AU summit meeting on Friday.
The Boko Haram uprising has become a regional crisis, with the four directly affected countries - Cameroon, Chad, Niger and Nigeria - agreeing along with Benin to boost cooperation to contain the threat and to form a Multinational Joint Task Force (MNJTF).
"I am deeply concerned by the prevailing situation as a result of Boko Haram terrorist activities, including the recent escalation of violence witnessed on the ground," Dlamini-Zuma said after the meeting at AU headquarters in the Ethiopian capital, where the two-day annual summit of the 54-nation bloc is slated to be held.
"The continued attacks in northeastern Nigeria and the increasing attacks in the Lake Chad Basin, along the border with Chad and Cameroon, and in the northern provinces of that country, have the potential of destabilising the entire region, with far-reaching security and humanitarian consequences."
More than 13,000 people have been killed and about one million made homeless by Boko Haram violence since 2009.
Regional nations pledged earlier this month to commit a battalion each to the force, a total of some 3,000 troops, but Dlamini-Zuma said after meetings
Chad's President Idriss Deby, who earlier this month sent a convoy of troops and 400 military vehicles into neighbouring Cameroon to fight Boko Haram, said action had to be taken.
"We have seen too many meetings and no concrete action," Deby said.
"Today, there are four countries affected by Boko Haram, but tomorrow it may be a continental problem."
Nigeria has the largest army in west Africa but has come under criticism at home and abroad for failing to stop the advance of Boko Haram.
Earlier this month Nigerian security officials ruled out the need for a United Nations or African Union-backed force to fight Boko Haram, saying the country and its partners could handle the threat.
But international pressure has ramped up, with a top US military commander General David Rodriguez, head of US Africa Command, warning this week that tackling Boko Haram will need a "huge" international effort.