China says it will allow tourists to visit disputed islands in the South China Sea, a move likely to further inflame tensions over the vast maritime region.

Beijing's plans for the Paracel islands are likely to irritate Vietnam, which also claims the islands as part of its territory. Hanoi issued a statement last week denouncing a sailing race around the Parcels staged by authorities in China's Hainan province.

In remarks first broadcast by Chinese state radio, officials say the tourist visits can help China strengthen its claim over the islands, which are called Xisha in Chinese.

Beijing has become increasingly assertive about its claims over the entire 3.5 million-square-kilometer South China Sea, putting it at odds with Vietnam and other regional rivals, including the Philippines, Malaysia and Brunei, which also claim parts of the waterway as their own.

At this week's summit of the Association of Southeast Asian Nations, the leaders of the 10-member bloc pledged to quickly complete work on a code of conduct to resolve conflicts with China in the potentially resource-rich area.