Updated

U.S. Secretary of State John Kerry says China would be committing a provocative and destabilizing act if it establishes an air defense zone in the South China Sea.

Kerry says doing so would raise tensions between China and other Asian countries. He says such an act also would call into question China's commitment to resolving disputes over islands and maritime claims diplomatically.

Kerry says the U.S. doesn't take sides on competing claims. He says no country should move unilaterally to militarize the resource-rich region.

Kerry spoke to reporters while visiting Mongolia. He travels on to China later Sunday for annual U.S.-China strategic and economic talks.