China must cease its activities around Tri Ton Island in the Hoang Sa Archipelago (Paracel Islands), a Vietnamese government spokeswoman announced at a press conference held Thursday.
Since late May, China has dispatched the M/V Western Spirit and several escort vessels to conduct seismic surveys around the islands, according to Nguyen Phuong Nga of the Ministry of Foreign Affairs.
Nga alleged that, during the exercises, the Chinese ships have explored oil and gas lots No.141, 142 and 143 on Vietnam's continental shelf, some 90-117 nautical miles from the central province of Quang Ngai.
The actions critically violate Vietnam's undisputable sovereignty over the islands and its continental shelf, the spokeswoman said.
China is also violating the country's Exclusive Economic Zone (EEZ) of 200 nautical miles which is generated under the United Nations Convention on Law of the Sea, and against the Declaration on the Conduct of Parties in the South China Sea (DOC) signed in 2002, Nga stressed.
Under the UN convention, every state controls the resources found in its EEZ and has the right to regulate the behavior of other states within that territory.
Vietnam's Ministry of Foreign Affairs has met with Chinese officials at different ranks and stated the country's opinion about the East Sea matter. So far, China has not curbed its actions.
"Vietnam demands that China immediately cease violating Vietnam's sovereignty, and its sovereignty in the East Sea," Nga said.
The spokeswoman concluded by stating that China must contribute to the preservation of the East Sea's peace and stability, and promote a steady and healthy dialog between the two nations.