U.S. Secretary of State John Kerry is pressing for peaceful resolutions to increasingly tense maritime disputes in Asia and urging China to take a firmer stand on North Korea's nuclear program.

He's set to leave Saudi Arabia on Sunday for stops in Laos, Cambodia and China.

Laos is the current head of the Association of Southeast Asian Nations. Its members are becoming more vocal in complaints about China's growing assertiveness over competing claims in the South China Sea.

U.S. officials say Kerry will make the case for the 10-nation group to present a unified front in dealing with the Chinese.

In China, Kerry is expected to argue for Beijing to do more to push North Korea to halt nuclear tests and return to disarmament talks.