A Chinese survey ship that has been embroiled in a tense standoff with Vietnamese vessels has headed away from Vietnam's exclusive economic zone, a Washington-based think tank said on Wednesday.

Since early July, Vietnamese ships have closely tracked Chinese vessels operating within its EEZ, in the latest confrontation in waters that are a potential global flash point as the United States challenges China's sweeping maritime claims.

"Ship tracking data show that China's survey ship has exited the Vietnamese EEZ for now, but at least two of its coast guard escorts remain in the area of the survey," said Devin Thorne, senior analyst at the Center for Advanced Defense Studies, citing data from maritime analytics company Windward.