Under a "global and regional action plan" firmed up to face the challenge posed by Boko Haram, the governments of Nigeria, Benin, Cameroon, Niger and Chad will share intelligence and border surveillance in the hunt for the girls still held by the militants.
Western nations will provide technical expertise and training to the new regional African effort against the extreme Islamists.
"Boko Haram is no longer a local terror group. It is clearly operating as an al Qaeda operation" in central Africa, Nigerian President Goodluck Jonathan said while speaking at a summit hosted by French President Hollande in Paris yesterday.
"We have shown our commitment for a regional approach. Without West African countries coming together we will not be able to crush these terrorists," he said amid criticism that his governemnt has done enough to rescue the schoolgirls abducted last month.
Jonathan said Nigeria has deployed 20,000 troops, aircraft and intelligence sources in areas where Boko Haram is active.
"The major challenge that we have faced in our search and rescue operation so far has been the deluge of misinformation about the whereabouts of the girls and the circumstances of their disappearance," the President said.
Last month, Boko Haram abducted 223 schoolgirls in north -eastern Nigeria, where it is based. It released a video earlier last week showing over 100 of the girls and offering an exchange for prisoners.
President Jonathan has ruled out negotiations over their possible release, officials say.
Boko Haram's guerrilla campaign has claimed 12,000 lives, with 8,000 people injured since 2009, Jonathan said at the summit which brought together Presidents of west African countries of Benin, Cameroon, Niger and Chad.
Hollande said the "global and regional action plan" to face the challenge posed by Boko Haram involved "co-ordinating intelligence, sharing information... border surveillance, a military presence notably around Lake Chad and the capacity to intervene in case of danger".
Hollande called Boko Haram a "major threat to West and Central Africa", and said it had links with al-Qaeda's North- African arm and "other terrorist organisations".
Speaking at a press conference, Cameroon's President Paul Biya said: "We are here to declare war on Boko Haram".
"There is determination to tackle this situation head on ... to launch a war, a total war on Boko Haram," Chad's President Idriss Deby said.
Boko Haram translates as "Western education is a sin". The militant group says its aim is to impose a stricter enforcement of Sharia law across Nigeria, Africa's most populous nation, which is split between a majority Muslim north and a mostly Christian south.
Representatives from the UK, US and EU also took part in the Paris meeting.
Nigeria will coordinate patrols, pool intelligence and exchange weapons and human trafficking information with Benin, Cameroon, Chad and Niger, according to the agreement reached at the summit.
France, the United States, the United Kingdom and the European Union "will coordinate their support for this regional cooperation" through technical expertise, training programs and support for border-area management programmes, a summit statement said.
The participants agreed that the United Kingdom will host a follow-up meeting next month to review the action plan.
In the meantime, participants committed to accelerating international sanctions against Boko Haram and its leaders through the United Nations, CNN reported.
Senior State Department official Wendy Sherman said these could be proposed to the Security Council as early as next week.
She hailed the discussions as "very positive and very focused".
"We are going to see ever improving and coordinated action," Sherman said.
As the summit took place, reports emerged about the latest apparent Boko Haram attack, this one in Cameroon.
Hollande said one Cameroonian soldier was killed in the Friday night attack against Chinese nationals in northern Cameroon, which is known as a stronghold for the Islamic extremists.
Ten Chinese nationals are missing after the attack, a Chinese official said.