"Vietnamese authorities constantly monitor all activities on Vietnamese sea regions as determined by the United Nations Convention for the Law of the Sea (UNCLOS)," Foreign Ministry spokeswoman Le Thi Thu Hang said at Thursday’s press meet.

The statement came in the wake of Indonesia deploying fighter jets and naval ships to the East Sea, known internationally as the South China Sea, on Tuesday in a stand-off with Beijing.

The actions followed Jakarta protesting Chinese violations of Indonesia’s exclusive economic zone (EEZ), Reuters reported.

The stand-off began in mid-December when a Chinese coast guard vessel, accompanying Chinese fishing boats, entered waters off the coast of Indonesia’s northern Natuna islands, prompting Jakarta to summon Beijing’s ambassador and lodge a complaint.

"Parties should not complicate the situation and should make practical and appropriate contributions to positively develop and maintain peace and stability while fostering friendly, collaborative relations in the region," Hang said.

She was responding to a question about Malaysia submitting a report on extended continental shelf on the South China Sea to the United Nations on December 12 last year. This has sparked concerns that the extended continental shelf as claimed by Malaysia could overlap with claims by other countries.

Hang also drew attention to the Vietnam-Malaysia Joint Submission on the limits of the continental shelf beyond 200 nautical miles from baselines at the southern regions of the South China Sea that both countries submitted to the United Nations’ Commission on the Limits of the Continental Shelf (CLCS) at a meeting in New York in August 2009.

"Vietnam reserves sovereignty rights over the extended continental shelf, beyond the 200-nautical-mile [limit] [into] the central regions of the East Sea, as stated in the diplomatic note sent to the CLCS in 2009," Hang said.