TOKYO - Leaders from Japan and 10 Southeast Asian countries on Saturday pledged to cooperate in ensuring freedom of navigation during a summit overshadowed by concerns over China's growing assertiveness in the region.

A joint statement issued after the summit meeting refrained from an explicit mention of China's recent declaration of a maritime air defense zone over the East China Sea. But it was the backdrop behind the promise to cooperate to ensure "freedom of overflight and aviation safety in accordance with universally recognized principles of international law."

"To the Chinese, we are calling on the withdrawal of all the measures that violate these general principles," Japanese Prime Minister Shinzo Abe said. He said Japan would stick to its decision advising airlines to continue their operations as they had before China's announcement.

"Raising tensions in this region is to nobody's advantage," Abe said in a nationally televised news conference showcasing what he called Japan's "special partnership" with the Association of Southeast Asian Nations.

The summit marks 40 years of ties between Japan and ASEAN, a resource-rich region of more than 600 million people. Abe has visited all 10 ASEAN countries in the past year, seeking to boost both security and business ties, a warm contrast to frosty relations with China.