A Vietnamese fishing boat capsized this week after it struck a Chinese vessel near a Chinese oil rig deployed in disputed waters.
Reacting to reports the Chinese intentionally rammed the Vietnamese boat, State Department spokeswoman Jen Psaki said both sides were called on to exercise restraint. "Provocative actions" from the dispute, she added, "have largely been from the Chinese side."
China says it's operating within its maritime borders, though Vietnam said the rig's deployment is a violation of international laws.
The U.S. government has said it has no stance on who has sovereign claims to the territory in question.
Qin Gang, a spokesman for the Chinese Foreign Ministry, said Tuesday the Vietnamese fishing boat was harassing Chinese vessels in the waters near the Xisha Islands. The Vietnamese actions, the official Xinhua News Agency reported, were a deliberate attempt to disrupt regular operations from a Chinese company operating in Chinese waters.