China has abruptly cut short military talks with Vietnam, raising fears of a spike in tensions over disputed territory in the South China Sea.
Chinese state media reported that General Fan Changlong, the vice-chairman of the Central Military Commission, had returned early from a visit to Vietnam following talks with the country’s most senior leaders.
China also cancelled a scheduled meeting on border security, citing unspecified “working arrangements”.
The unexplained breakdown signals a potentially dangerous rupture after a period in which both sides attempted to ease the confrontation over their territorial disputes.
Analysts speculate that China has been angered by Vietnam’s moves to develop energy reserves in waters off its coast which are also claimed by Beijing.
Vietnam has opened up an area for oil exploration near Vanguard Bank in the western Spratlys.
It insists that the feature lies on its own continental shelf, some 300km from the Mekong Delta, and so cannot be included in the areas claimed by China.
Beijing may have demanded the cancellation of the project because of an agreement by the two sides not to drill in disputed areas.
China also feels challenged by a gas venture further north involving PetroVietnam and Exxon Mobil.
Chinese leaders have been annoyed in recent weeks by Vietnam’s drive for closer strategic ties with Japan and the United States, including visits to Washington and Tokyo by the Prime Minister, Nguyen Xuan Phuc.
Unconfirmed reports say that China is deploying large numbers of vessels in the contested area and could be preparing to deploy a drilling rig of its own.
Beijing is showing signs of losing patience with Vietnam, which remains resolute in defence of its territorial claims while other ASEAN countries have been showing signs of weakness.