BEIJING – China insisted Thursday it had every right to drill for oil off Vietnam's coast and warned its neighbor to leave the area around the deep-sea rig where Chinese and Vietnamese ships are engaged in a tense standoff.
With the ships jostling each other since China deployed the rig last weekend in disputed South China Sea waters, the United States warned both sides to de-escalate tensions and urged China to clarify its claims to the territory.
The stalemate underlines the apparently intractable nature of many of China's territorial disputes with its neighbors and the ship standoff -- with both sides accusing the other of ramming ships -- has raised the possibility of a conflict in the South China Sea's most serious incident in years.
Vietnam's main stock market index recorded its biggest one-day drop since 2001 on fears of a protracted stalemate or possible conflict between the neighboring nations, which have fought two naval skirmishes in the waters since 1974 and have history of conflict going back 1,000 years.
The standoff started May 1 when China moved a deep sea oil rig into waters close to the Paracel Islands in what most analysts believe was an especially assertive move to help cement its claims of sovereignty over the area. Vietnam, which says the islands belong to it, immediately dispatched ships.
On Wednesday, Vietnam said Chinese vessels had repeatedly rammed and fired water cannons at its ships, damaging several of them, and showed video footage of the incidents. China insists it is doing nothing wrong and said Thursday it had "maintained a lot of restraint" in the face of "intensive provocations" by Vietnam that were endangering its personnel and property.
It has said it will continue with its drilling activities while the area is typhoon-free in May, June and July.
"It's the Vietnamese vessels that are provoking this issue. It's the Vietnamese vessels that are ramming into Chinese vessels," said Yi Xianliang, deputy director general of the department of Boundary and Ocean Affairs of China's Foreign Ministry.
Yi said China's operations in the waters were "completely legal, legitimate and justified" because the waters were "China's inherent territory."
He said Vietnam had within five days dispatched 35 vessels that had rammed Chinese ships 171 times. He said the Vietnamese ships included armed vessels, but on the Chinese side there were only civilian or non-armed government vessels.
Yi said China stood ready to discuss the issue with Vietnam, "but the precondition is that Vietnam must put an end to the disruption of Chinese operations and must remove its vessels and personnel at the scene."
Ngo Ngoc Thu, deputy commander of Vietnam Coast Guard, said the situation remained tense but there had been no contact Thursday.
"The two sides are still shadow boxing with each other," he told The Associated Press.
China has been increasingly pressing its claims in the South China Sea, which it claims almost in its entirety. This is bringing it into conflict with Vietnam and the Philippines, which also claim parts of the water, as do Malaysia, Brunei and Taiwan.
Li Mingjing, a China security expert at Singapore's Nanyang Technological University, said that while the rig's deployment was primarily part of long-term plans by state-owned China National Offshore Oil Company to exploit energy resources in the South China Sea, it would also consolidate Chinese sovereignty over the area.
"Concessions to Vietnam are extremely unlikely since that would weaken China's territorial claim," Li said.
The United States position is that it doesn't take sides in the dispute, but it too shares regional concerns about China's growing clout. It has criticized Beijing's latest move as "provocative."
Daniel Russel, the assistant secretary of state for East Asia and the Pacific, urged both sides to use restraint and avoid taking unilateral actions, and urged China to detail its legal claims to the waters.
"The global economy and the region's economy are too important and too fragile to brook the possibility of a crisis that could escalate into conflict," he told reporters in the Vietnamese capital, Hanoi. "My simple message is to restate the importance of restraint, dialogue and adherence to international law."