Eight warships set sail from the port of Zhanjiang, in China's southern Guangdong province, with 1,200 military personnel taking part in the event, according to Chinese state broadcaster CCTV.

Beijing's expansive claims to the South China Sea have long been a source of friction with rival claimants in Southeast Asia, as well as Washington which has traditionally been the dominant naval power in the area.

The navies of China and the 10-member Association of Southeast Asian Nations (ASEAN) agreed to hold the week-long manoeuvres as part of efforts to promote stability and ease tensions across the disputed sea.

Singapore, which is co-organising the event, Brunei, Thailand, Vietnam and Philippines deployed ships to participate in the exercise, according to China's defence ministry.

Cambodia, Indonesia, Malaysia, and Myanmar sent observers, according to CCTV.

Exercises are expected to include a joint search and rescue operation and communication exercises while in formation, the Chinese defence ministry said in a statement late Sunday.

The joint naval exercises are taking place after preparatory tabletop exercises were held in Singapore in August between ASEAN and China.

In a speech during Monday's opening ceremony, Singapore chief of navy, Rear-Admiral Lew Chuen Hong emphasised the security benefits, as well as economic growth, to be reaped from regional collaboration, reported The Strait Times.

"To allow the stable and collective use of a shared space, a set of common rules and understanding is very important," he said.

The Chinese defence ministry said Sunday the exercises would "enhance mutual trust" and "help promote military relations between China and ASEAN countries, strengthen maritime security cooperation, and enhance the ability to jointly respond to security threats."

Attending an ASEAN ministerial meeting where the drill was announced on Friday, US Defense Secretary Jim Mattis said he did not believe the exercises were "contrary" to US interests.

The United States has raised concerns about China's installation of military facilities in artificially-built islands in the South China Sea, and routinely conducted "freedom of navigation" operations to challenge Beijing's territorial claims.