Japan and Southeast Asian nations have called for freedom of the high seas and skies, amid heightened tensions over China's new air defence zone in the East China Sea.
The statement, issued at a regional summit in Tokyo, also calls for disputes to be resolved by peaceful means.
China's recent announcement of an air defence zone over islands in the East China Sea, which are claimed by both Tokyo and Beijing, triggered protests from Japan, the United States and South Korea.
China is also locked in territorial rows with other Asian nations over wide swathes of the South China Sea, including waters claimed by several members of the Association of Southeast Asian Nations.
Reuters reports Beijing has said it might set up a similar air defence zone there as well.