United States national security adviser Jake Sullivan met with a top Chinese military official on Thursday as the two countries strengthen communication to prevent differences over the South China Sea and Taiwan from spiralling into conflict.

The meeting came one day after the White House said both countries would plan for a phone call between Chinese President Xi Jinping and US President Joe Biden in the coming weeks.

Mr Sullivan was wrapping up a three-day trip to China, his first as national security adviser and one aimed at stabilising bilateral relations to avoid conflict.

His main talks were held over the past day and a half with Wang Yi, the foreign minister and the ruling Communist Party’s top foreign policy official.

A White House statement on Wednesday after talks with Mr Wang concluded said both sides would keep lines of communication open, including planning for a “leader-level call” in the coming weeks.

The Chinese Foreign Ministry said Mr Wang and Mr Sullivan discussed “a new round of interactions between the two countries’ heads of state to take place in the near future”.

There was no indication whether the two leaders might meet in person before Mr Biden leaves the Oval Office in January.

Mr Sullivan’s meeting on Thursday was with Zhang Youxia, one of two vice chairs of the Central Military Commission, an organisation Mr Xi personally heads.

It was a rare meeting with a civilian US official.

“Your request to meet with me shows the value you attach to military security and the relationship between our militaries,” Mr Zhang told Mr Sullivan in opening remarks.

A White House statement after the talks said the two had “recognised the progress in sustained, regular military-military communications over the past ten months” and noted the agreement to hold a telephone call between commanders at the theatre level in the future.

Any potential call would be between Admiral Samuel Paparo, who heads the US Indo-Pacific Command in Hawaii, and his Chinese counterpart, said Danny Russel, a vice president at the Asia Society Policy Institute in New York.

“This theatre command-level dialogue is critical for crisis prevention but something the Chinese military has been resisting,” Mr Russel said.