A former government official urged Vietnam to appeal to the United Nations about China's latest violation of Vietnam's maritime sovereignty.
On Thursday, three Chinese surveillance ships illegally entered Vietnamese waters and violently disrupted a routine siesmic survey being conducted by a state-owned gas company.
"[Vietnam] should submit the case to international judicial bodies, [including] the International Tribunal for the Law of the Sea," Tran Cong Truc, former head of Vietnam's Government Border Committee told local media following the incident on May 26. "If decisive action isn't taken, China's behavior will escalate."
Earlier that day, Chinese vessels cut exploration cables connected to the Binh Minh 02 and chased the ship out of the area.
The Vietnamese vessel belonged to the National Oil and Gas Group (PetroVietnam) and was in the middle of conducting a seismic survey on the nation's continental shelf.
The incident took place in an area called Block 148 about 120 km (80 miles) from the beach town of Nha Trang, and some 600 km (370 miles) south of China's Hainan island.
On Saturday, the Ministry of Foreign Affairs issued a statement demanding that China immediately cease and desist such behaviors.
The ministry spokeswoman Nguyen Phuong Nga demanded that China never again violate Vietnam's sovereignty and jurisdiction over its continental shelf and exclusive economic zone.
Truc said Vietnam always strives to take peaceful actions but warned that when its territorial sovereignty is violated, "we are justified in using all proper and legitimate measures to protect our solemn national sovereignty."
"Recently, Malaysia and the Philippines chased Chinese ships violating [their territory] away using aircrafts and armed forces," he said.
"Every nation has the right to ensure national security and defend its rightful interests."
Based on international laws, Truc said China had publicly violated the 1982 Convention on the Law of the Sea, to which Vietnam and China are both signatories.
"These are waters fall wholly under Vietnam's sovereignty," he said of the location of the incident. "They do not overlap and this is not a disputed area."
Truc said he was not surprised by China's latest actions because they figure into its plan to claim 80 percent of the East Sea.
Since the 1950s, China has continuously attempted to assert its sovereignty over the East Sea at international forums, he said.
Truc was concerned that this recent incident could have a bad impact on regional security.
"This raises a question throughout the region: why has China continuously taken action to turn its ambition into reality? [These actions] could not only affect regional security and national defense but also economic and civilian activities," he said.
"It would also obstruct one of the most important shipping lines in the East Sea. I think countries throughout the region should raise a common voice over China's latest action."
Truc also stressed that China's recent indiscretion occurred 84 nautical miles inside Vietnam's Exclusive Economic Zone.