WASHINGTON -- Indonesia's president is calling for all parties in the disputed South China Sea to exercise restraint and for China and Southeast Asia's regional bloc to start discussions on the substance of a code of conduct to manage tensions there.

President Joko Widodo was speaking in Washington Tuesday, hours after a U.S. Navy warship sailed past one of China's artificial islands in the South China Sea in a challenge to Chinese sovereignty claims, drawing an angry protest from Beijing.

Widodo did not directly refer to the U.S. action. He underlined the neutrality of Indonesia, which is the largest Southeast Asian nation but doesn't count itself as one of the claimants to the disputed islands and reefs.

He said Indonesia is ready to play "an active role" in resolving the dispute.