The appointment of Liu to replace Defence Minister Li Shangfu - which one of the people said was likely to happen before Beijing holds an international security forum later this month - could boost military engagement with the United States amid regional tensions, three military analysts told Reuters.

Li was sanctioned by the U.S. in 2018 for an arms deal he secured with Russia in an earlier role. China has demanded the curbs - which include a visa ban and prohibitions on conducting U.S. financial transactions - be lifted. Liu, 59, is not under Western sanctions.

Currently the Chief of the Joint Staff Department of the Central Military Commission (CMC), Liu was described as Li's likely replacement by a person with direct knowledge of the matter, as well as two people close to the military and two regional officials with close knowledge of Chinese politics. They spoke on condition of anonymity due to the confidential nature of the information.

China's defence ministry and State Council information office did not respond to requests for comment. Reuters was unable to reach Liu himself for comment.

A U.S. Department of Defense spokesperson declined to comment on Liu's possible appointment but said the U.S. "continues to believe in the importance of maintaining open lines of military-to-military communication" with China.

Li's absence has not been officially explained, though Reuters reported last month that he was under investigation for corrupt procurement of military equipment in a previous role.

If his departure is confirmed, Li will be the second senior minister to lose his job in recent months.

Qin Gang was removed as foreign minister in July, one month after he was last seen in public.

It is unclear whether Li will retain his position as one of China's five state councillors, a post outranking a regular minister. Qin has not been officially removed from his post as state councillor.

Any decision to improve military-to-military ties - frozen by Beijing when then-U.S. House Speaker Nancy Pelosi visited Taipei in August 2022 - would be made by President Xi Jinping, who has the ultimate say in all important policies and appointments.

Xi is also Commander-in-Chief of the armed forces and chair of the CMC, China's top defence decision-making body, on which Liu already sits.

The person with direct knowledge of the matter said Liu's appointment would likely be announced before foreign defence officials visit Beijing on Oct. 29-31 for the Xiangshan Forum, a major international security seminar.

Procedurally, the appointment and removal of high-level officials is announced by the National People's Congress Standing Committee, which takes guidance from the Chinese Communist Party's elite Politburo. The politburo is expected to meet at the end of this month.

"If Xi Jinping is indeed intent on re-engaging in top-level military engagement with the U.S., this could well present an opportunity for the Pentagon to finally reconnect with the (People's Liberation Army) high command," said James Char, a scholar at Singapore's S. Rajaratnam School of International Studies.

Reuters reported Wednesday that Washington has accepted an invitation to the Xiangshan Forum, though it is unlikely that Defense Secretary Lloyd Austin will personally attend.

PUBLIC FACE OF THE MILITARY

China's Minister of National Defence has a largely diplomatic role with no direct command authority. The post is subordinate to a handful of other officials from the CMC, including the two vice chairmen under Xi.

Liu's appointment could elevate the profile of the job, five analysts and military attaches told Reuters.

His recent experience leading the Joint Staff Department would allow foreign counterparts to deal with a figure at the centre of China's military operations and war planning, rather than a mere technocrat.

U.S. defence officials have long wanted to reestablish routine communications with counterparts directly involved in command decisions.

"This could really help breathe some oxygen into China's military diplomacy," said Singapore-based defence analyst Alexander Neill, an adjunct fellow at the Pacific Forum, a foreign policy research institute in Honolulu.

"Finally, the U.S. might have someone they would really want to talk to," he said.

Liu is also one of the few recent Chinese military leaders with combat experience, having been involved in intense border fights with Vietnamese troops in 1986 - part of years of skirmishes that followed Beijing's invasion of northern Vietnam in 1979, according to Chinese media reports.

ONE-MAN RULE

Defence diplomacy is seen by diplomats and analysts as an important part of Xi's push for a modernized military that can support China's growing international interests.

China's ships and planes will need greater access to ports and bases internationally to achieve Xi's goal of becoming the dominant world power.

The removal of two senior ministers in such quick succession "highlights the severe limitation of Xi's one-man rule," said Willy Lam, senior fellow at U.S. think tank Jamestown Foundation.

"He prioritised loyalty over capability and honesty when choosing who to put in power. Look how they turned out?"

Xi has made combating corruption a priority, particularly within the military, since he first became president. His defenders say the centralisaton of power is needed if China is successfully to navigate global tensions.

Qin was made foreign minister in Dec. 2022 and Li became defence minister in March. State news agency Xinhua reported in October 2022 that Xi decided on the senior appointments after personally conducting interviews with all the prospective candidates.

Air Force commander Chang Dingqiu is set to take over from Liu as Chief of the Joint Staff Department, according to three of the people familiar with the situation.