NATO's chief says it's not sufficient for the alliance to reinforce its own armed forces, it must also help partner nations in the Middle East and North Africa that are threatened by extremist violence.

"For our nations to be safe, it's not enough to keep our defenses strong, we must help to make our partners stronger," NATO Secretary-General Jens Stoltenberg said Friday, several hours before the opening of a landmark summit meeting of alliance heads of state and government.

"Training local forces is often our best weapon against violent extremism," Stoltenberg told a forum of defense and security experts. Among the items on the NATO summit's ambitious agenda is increased assistance for Iraq's military, extension of the West's financial commitment to the Afghan military and police, and aid for Tunisia.