Members of the Vietnamese National Assembly met Tuesday in Hanoi to discuss a decision by China National Offshore Oil Corp. to deploy rig HD-981 about 120 miles off the coast of Vietnam.
National Assembly Chairman Nguyen Sinh Hung said the situation in the South China Sea was getting complicated.
"China's recent deployment of a giant oil rig and its protective armada in Vietnam's [exclusive economic zone] seriously violates Vietnam's territorial sovereignty," he said.
A government report submitted Tuesday to the assembly says Vietnam reserves the right to maintain a posture of self-defense in the event the situation escalates.
China says it's operating within its territorial waters. The U.S. government has weighed in, saying it has no stance on claims to the South China Sea, but China was acting provocatively in the disputed waters.
The Chinese government this week began evacuating its nationals from Vietnam in response to ongoing anti-China demonstrations.