Vietnamese Prime Minister Nguyen Tan Dung has threatened legal action against China for placing a state-owned oil rig in disputed waters off Vietnam's coast.
In emailed statements to reporters Thursday, Prime Minister Dung said Vietnam is considering "various defense options, including legal actions" in response to the oil rig placement.
The statement comes as Vietnamese and Chinese ships continue a tense standoff near the deep-sea oil platform. The vessels have rammed into each other and exchanged water cannon fire, raising fears of a wider clash.
Dung stressed that Hanoi will "resolutely defend its sovereignty," but said he will only use defensive military action, saying he does not wish to start a war.
On May 1, Beijing moved the oil rig to an area near the Paracel Islands in the South China Sea, within what Vietnam considers its exclusive economic zone.
The dispute has led to anti-Chinese protests in Vietnam that have killed at least two people and injured dozens.
It is the latest move by Beijing to aggressively stake its claims to disputed areas of the South China Sea.
Prime Minister Dung made his comments after meeting in Manila with Philippine President Benigno Aquino, whose government also has a territorial dispute with Beijing in the South China Sea.
The Philippines earlier this year challenged the legality of China's maritime claims to an international tribunal in The Hague. Beijing was angered by the move and has refused to participate in the case.
China rejects using international arbitration or regional groupings to solve the conflicts. It instead prefers dealing with each rival claimant separately, a position that gives it considerably more clout.
Beijing claims nearly all of the 2.5-million square kilometer South China Sea, putting it at odds with the claims of the Philippines, Vietnam, Brunei, Malaysia, and Taiwan.