Vietnam has been attempting to rally other southeast Asian nations against Beijing and is building new defense relationships with Japan, the US and India. Meanwhile, under intense Chinese pressure, Vietnam was forced to suspend offshore drilling in Chinese-claimed waters in July.
Vietnamese Foreign Ministry spokeswoman Thi Thu Hang said in a statement that Hanoi was very worried about Beijing’s maneuvers in the Gulf of Tonkin, at the northern end of the South China Sea. She did not specifying what drills she was referring to.
"Vietnam proposes China to cease and refrain from repeating acts that complicate the situation in the East Sea," Hang said, according to Reuters. She added that any and all foreign activity in Vietnamese waters must comply with international and Vietnamese regulations.
The drills are routine annual exercises, according Chinese Foreign Ministry spokeswoman Hua Chunying. She told a Friday news briefing that Beijing has the right to conduct drills in the waters in question because "the relevant sea is under China’s jurisdiction."
"We hope the relevant side can calmly and rationally view it," Hua said.
China’s Maritime Safety Administration said last month that drills would take place from August 29 until September 4 in waters east of Vietnam, including live-fire drills near the Paracel Islands, claimed by China, Taiwan and Vietnam.
Southeast Asian affairs expert Dai Fan from Guangzhou’s Jinan University said that maritime issues have wedged a "huge gap" between Vietnam and China.
"Now is a critical time for Vietnam, since Japan and the US are both trying to build their relationships with Vietnam. Japan has increased investments in the country, and the US has long been seeking deeper military ties with Vietnam," he said.
Roughly $3 trillion in international trade passes through the South China Sea each year, the vast majority of it coming or going from China. In addition to China, Taiwan and Vietnam, the Philippines, Brunei and Malaysia have claims in the waterway.
In November, US President Donald Trump is expected to attend the Asia-Pacific Economic Cooperation summit held in Vietnam.