U.S. National Security Adviser Jake Sullivan met one of Chinese President Xi Jinping's top military officials on Thursday as he wrapped up three days of talks in Beijing intended to ease simmering tensions between the two superpowers.

Sullivan was expected to push for enhanced working-level military to military communications in his session with General Zhang Youxia, vice chairman of China's paramount military body, the Central Military Commission, White House officials said.

It is the first meeting between Zhang and a Biden administration official, and the first between a senior U.S. official and a vice chair of the commission since 2018.

"Your request for having this meeting with me demonstrates the value the U.S. government puts on military security and our military-to-military relationship," Zhang said as the pair met at the Ba Yi Building - the headquarters of the People's Liberation Army.

"I know it is rare that we have the opportunity to have this kind of exchange and given the state of the world and the need for us to responsibly manage U.S.-China relations, I think it's a very important meeting," Sullivan replied.

Zhang is believed to be close to Xi and has survived turmoil in the country’s military ranks. Western and Asian diplomats say he is more powerful than China's defence minister, who more frequently meets foreign officials.

Sullivan will also talk further with China's top diplomat Wang Yi on Thursday, seeking to calm tensions ahead of the Nov. 5 U.S. election.

"The key to the smooth development of China-U.S. interaction lies in treating each other as equals," Wang told Sullivan, according to state broadcaster CCTV.

"The two sides held candid, substantive, and constructive discussions on a range of bilateral, regional, and global issues," the White House said.

In the final months of his presidency, Biden has pushed direct diplomacy to influence Xi and keep those tensions at bay; U.S. Vice President Kamala Harris, the Democratic candidate in November's election, would likely pursue a similar strategy.

Beijing plans to express its disapproval over U.S. tariffs on a range of manufactured goods and export controls targeting Chinese chip makers, and talk about its claims of sovereignty over democratically ruled Taiwan.