China dispatches patrol boat amid tensions

China has dispatched one of its largest maritime patrol ships on a first-ever visit to the Southeast Asian city-state of Singapore amid a spike in tensions over disputed territory in the South China Sea.

The Haixun-31 left Wednesday and will stay in Singapore for two weeks of exchanges on search and rescue, anti-piracy and port management operations, Chinese state media reported Thursday.

Similar ships have been accused of harassing foreign shipping in the South China Sea, including U.S. Navy surveillance vessels.

China, Vietnam and the Philippines have traded diplomatic barbs recently over claims to the resource-rich South China Sea and its island groups. Vietnam's navy conducted live-firing exercises Monday after accusing Chinese boats of disrupting oil and gas exploration in its waters.

U.S. State Department spokeswoman Victoria Nuland told a news conference Friday that the U.S. understood the Chinese ship was making a "routine, planned visit" to Singapore. She reiterated that the South China Sea disputes should be resolved through negotiations.

The 3,000-ton, helicopter-equipped Haixun-31 is one of two vessels of that size belonging to the Maritime Safety Administration, one of five nominally civilian agencies tasked with overseeing China's interests at sea. All of those departments are undergoing major expansions as Beijing moves to assert its territorial claims and economic interests in both the South China Sea and the East China Sea, where it has territorial disputes with Japan and Taiwan.

In coming years, three dozen vessels will be added to the fleet, an unnamed official with the State Oceanic Administration, another of the five agencies, announced last year. Defense experts say the People's Liberation Army Navy, which is also undergoing a thorough upgrade, has been gradually strengthening its command over the maritime patrol agencies, boosting their armaments and improving coordination.