Vietnam officials have warned China against drilling an oil rig in borderline waters in the South China Sea. Vietnam warning came following as Beijing steered a huge oil rig at the middle of a standoff between the two countries.

China has steered the HY-981 rig into an overlying area of inland shelves between Hainan Island in China and the central coast of Vietnam, Le Hai Binh, foreign ministry spokesperson of Hanoi said to GMA NEWS ONLINE. Vietnam has asked China to stop the drilling activities and to remove the rig out of the water, Binh added.

Hanoi closely observes the movement of the HY-981 oil rig, which caused the most horrible political breakdown in the middle of 2014 when China anchored the $1 billion rig for nearly ten weeks in Vietnam waters. Reuters said that Vietnam and China share over $60 billion in yearly trade but anti-China sentiments remain strong among the Vietnam people over the territorial breaches in the South China Sea.

Vietnam's anxiety over the rig develops subsequent to a recent flight testing carried out by China on a fake island in Spratly archipelago. According to China, most part of South China Sea is under its rule, while its neighbours like Philippines, Vietnam, Taiwan, Malaysia and Brunei have competing rights.

On Tuesday, demonstrators in Hanoi held an anti-China protest to spot the 42nd centenary of China taking full dominance over the Paracel Islands, Reuters said. According to the sources, Vietnam's report over the oil rig comes at a subtle time as Vietnam's communist heads prepare to elect their fresh leader to direct the nation for the following five years.

Vietnam's Politburo has suggested Mr.Trong continue his post as head of the nation's Communist Party while pro-West Prime Minister Nguyen Tan Dung to quit office, Wall Street Journal said citing people with knowledge of the situation.

According to reports, Dung has received domestic popularity for his condemnation of China's territorial infringement in the South China Sea. Prime Minister Dung is considered to be a modern politician who is ready to liberalize Vietnam economy.

TIME quoted London, a professor at the University of Hong Kong, as saying, "To his supporters, Dung, is Vietnam's most eloquent statesman, a reform champion, and a patriot keen to end Hanoi's deference to Beijing. Indeed, Dung projects a public commitment to market-liberalizing reforms and a willingness to expand freedoms 'in accordance with the law.'"

The reports said that the South China Ocean remains a tense topic for Vietnam leaders. Controversial frontiers in the Gulf of Tonkin and frequent flight testing by China over the disputed areas boost the tension between Vietnam and China.