China plans to set up an "international maritime judicial center" to help protect the country's sovereignty and rights at sea, its top judge said.

Giving a work report at the annual meeting of China's largely rubber-stamp parliament, chief justice Zhou Qiang said courts across China were working to implement the national strategy of building China into a "maritime power".

"(We) must resolutely safeguard China's national sovereignty, maritime rights and other core interests," he said. "(We) must improve the work of maritime courts and build an international maritime judicial center."

He gave no details. It is not clear when the judicial center may start working, where it would be located or what kinds of cases it would accept.

China disputes a group of uninhabited islets with Japan in the East China Sea, and also claims most of the South China Sea. Taiwan, Malaysia, Vietnam, the Philippines and Brunei also have competing claims there.

The Philippines has lodged a case with an arbitration court in The Hague about its dispute with China in the South China Sea, angering China which has pledged not to participate.

China's increasingly assertive claims in the South China Sea, along with its rapidly modernizing navy, have rattled nerves around the region.

Zhou said about 16,000 maritime cases were heard by Chinese courts last year, the most in the world. China has the largest number of maritime courts globally, he added.

Zhou pointed to a 2014 case at a southeastern China maritime court involving a collision between a Chinese trawler and a Panama-flagged cargo ship in waters near the islets China disputes with Japan in the East China Sea.

The case, which was ended via mediation, clearly showed China's jurisdiction over the region, he said.