Yaounde - The leaders of Nigeria and Cameroon pledged on Thursday to improve the exchange of intelligence and security co-operation along their border in a bid to tackle Nigerian Islamist militant group Boko Haram.Concluding his first visit to Cameroon since he was elected in March, Nigerian President Muhammadu Buhari and his Cameroonian counterpart Paul Biya voiced support in a joint statement for a planned multinational task force to fight Boko Haram, which has sworn allegiance to Islamic State.Buhari's visit came after the Nigerian militant group launched a wave of attacks in Nigeria, Cameroon, Chad and Niger that has killed hundreds of people in the past two months.The attacks follow a four-month military campaign by Nigeria, Chad and Niger that drove Boko Haram out of the towns of northeast Nigeria."The two heads of state note with satisfaction the weakening of the operational capabilities of Boko Haram," read a joint statement in French. "They expressed their common determination to eradicate Boko Haram and in this respect agreed to intensify intelligence sharing between their security services."Questions of fundingThe 8 700-strong task force of five nations near Lake Chad - Nigeria, Cameroon, Chad, Niger and Benin - was due to start operations from July 31, but has been dogged by questions of funding, co-ordination and political will."As a result of the promises made by the G7 to help the region to defeat Boko Haram, we are expecting some input in terms of training, equipment," Buhari told Cameroonian state television before his departure aboard a Nigerian air force plane. Biya took no questions.Some observers say little can be expected in terms of military activity before the end of the rainy season in September or October.The meeting was meant to soothe fractious relations between Cameroon and Nigeria, strained by a long-running border dispute that flared into conflict in 1993.Biya, in power since 1982, did not attend Buhari's inauguration and the Nigerian leader's trip comes nearly two months after he visited Chad and Niger. The two leaders agreed to meet again in Nigeria at a date to be confirmed.