Beijing has announced the successful conclusion of an oil rig's exploratory drilling at a site in the South China Sea that has witnessed more than 1,500 incidents of Vietnam sending ships to harass operations.

Experts said China should continue with its lawful maritime oil and gas development as planned and not be intimidated by moves taken and orchestrated by Hanoi and Washington.

Oil drilling platform HYSY981, operated and managed by China Oilfield Services Limited, completed the exploration and drilling operation in the sea near Zhongjian Island, part of China's Xisha Islands, on Tuesday, Foreign Ministry spokesman Hong Lei confirmed on Wednesday.