China's top foreign policy official is set to hold "candid" talks in Vietnam, Beijing said Tuesday as the countries intensify accusations over a maritime territorial dispute.

Foreign ministry spokeswoman Hua Chunying said State Councillor Yang Jiechi would Wednesday meet Pham Binh Minh, Vietnam's deputy prime minister and foreign minister.

They will "exchange views on issues concerning bilateral relations", Hua said at a regular briefing.

"State Councillor Yang Jiechi will have a candid and in-depth exchange of views with the Vietnamese side during his stay there," Hua said.

"We hope the Vietnamese side will bear in mind the larger interests of bilateral relations and work together with China to properly deal with the current situation."

Relations have plummeted since Beijing sent an oil rig last month to drill in a disputed area of the South China Sea.

The two sides have traded accusations in the increasingly heated row, with each side claiming the other has engaged in aggressive behaviour against its ships in the area, including ramming them.

Anti-Chinese riots sparked by Beijing's dispatch of the rig claimed three Chinese lives in Vietnam last month, according to Hanoi. Beijing says four Chinese citizens died.

Hua said Yang was going to Vietnam in his capacity as chairman of the Chinese side of the China-Vietnam Steering Committee for Bilateral Cooperation.

Asked whether the trip had been previously scheduled or recently arranged she said the committee chairmen meet every year but the precise time was decided on the basis of consultation between both sides.

Yang was previously China's foreign minister. But he moved up to the State Council, the country's cabinet, last year, making him more powerful than the current foreign minister.