BEIJING - China has moved an oil rig at the centre of last year's violent dispute with Vietnam closer to the latter's coast in the disputed South China Sea, just weeks ahead of the first visit by a chief of the Vietnamese Communist Party to Washington.
The move comes soon after Beijing indicated it was close to setting up new outposts in the maritime heart of South-east Asia, as it nears completion of land reclamation in the South China Sea.
China claims most of the potentially energy-rich sea, through which US$5 trillion (S$6.7 trillion) in ship-borne trade passes every year. The Philippines, Vietnam, Malaysia, Brunei and Taiwan all have overlapping claims.
China's deployment of the rig last year in what Vietnam called its exclusive economic zone (EEZ) and on its continental shelf, about 120 nautical miles off its coast, led to the worst breakdown in ties since a brief border war in 1979.
The Vietnamese remain embittered over a perceived history of Chinese bullying and territorial claims in the South China Sea, although Beijing said then that the rig was within its waters.
The rig now appears to be in an area where the EEZs of Vietnam and China overlap, but further away than last year, said visiting fellow Le Hong Hiep at the Institute of South-east Asian Studies in Singapore.
In an online statement posted on Thursday, China's Maritime Safety Administration said the "Haiyang Shiyou 981" rig would carry out "ocean drilling operations" 75 nautical miles south of the resort city of Sanya on southern Hainan island.
Experts estimate the site is 167km east of the Vietnam coast. The US$1 billion rig will remain there until Aug 20, the statement said, telling ships to stay 2,000m away for safety reasons.
Vietnam's maritime authorities are monitoring the rig's placement, the website of the country's state-controlled Tuoi Tre newspaper yesterday quoted unidentified sources as saying.
The rig's movement comes weeks before Vietnamese leader Nguyen Phu Trong is expected to visit the United States, in the first such trip by a general secretary of the nation's Communist Party.
His mission is set to enhance warming strategic ties between Washington and Hanoi - a relationship eyed warily in Beijing. It also comes amid rising concerns at China's rapid creation of artificial islands on South China Sea reefs - construction criticised by the US and protested by Vietnam.
However, Mr Le Hong Hiep felt Hanoi would not protest as strongly as it did last year if China said the rig was within an EEZ claimed from Hainan island, rather than one from the hotly disputed Paracel islands, as it did last year.
Vietnam and China agreed on an equal split of the maritime boundary of the Gulf of Tonkin in 2000, but have yet to agree on demarcating waters further south, near the rig's current site.