West African leaders have discussed setting up a force to combat extremists and will send an observation mission to Gambia before elections.
The decisions were announced after about a dozen heads of state, including presidents from Ivory Coast, Niger and Mali, met in Dakar, Senegal, for the 49th session of the Economic Community of West African States (ECOWAS).
"We must constantly reconcile the free movement of people and goods with security measures," said new president of the body Marcel Alain de Souza of Benin, at the opening of the day-long summit.
"The multiplication of the number of zones of terrorism in our space obliges us to share information on all activities and to co-ordinate and mobilise our resources."
The member states discussed the creation of a regional force, he said later, without giving further details.
The threat of extremism in the region has increased following major attacks by al Qaida-linked militants in Mali, Burkina Faso and in Ivory Coast.
Nigeria-based Boko Haram, which has declared its support for the Islamic State group, continues to carry out attacks in Nigeria, Cameroon, Niger and Chad.
Senegalese president Macky Sall, the outgoing chairman, said resources must be combined.
Liberian president Ellen Johnson Sirleaf was chosen to replace Mr Sall.
Ecowas also agreed to send a technical mission to Gambia ahead of December elections, calling for a free and credible vote and dialogue with the opposition.
"The conference urges the security forces to avoid excessive use of force against citizens," the leaders said.
Gambian activists and politicians have called on Ecowas to take action against Gambia for its recent brutal crackdown on rights to freedom of expression and peaceful assembly.
Dozens of people, including opposition leaders, have been arrested during recent demonstrations and one leader died from torture while in detention, according to human rights group Amnesty International.