Xi has waged an unrelenting crackdown on deep-seated corruption since coming to power a decade ago, a campaign critics say is a tool to purge political rivals.

China's former defence minister Li Shangfu was sacked abruptly last year in unexplained circumstances and replaced weeks later by the incumbent Dong Jun.

Xi addressed China's top brass on Monday at a meeting of the Central Military Commission in the northwestern city of Yan'an, state broadcaster CCTV said.

He urged participants to "eradicate the soil and conditions in which corruption thrives (and) expand the depth and breadth of the anti-corruption struggle", CCTV said.

Xi also called on the military to "strengthen the all-round supervision of senior cadres in exercising their duties and using their powers".

The meeting took place as China and its regional neighbours have butted heads in recent months over territorial claims in the hotly disputed South China Sea.

China also held war games last month around Taiwan, the self-ruled island that it claims as part of its territory and has vowed to seize one day, by force if needed.

"The situation in the world, country, party and army are undergoing complex and profound changes," Xi said, according to CCTV.

"We must unceasingly promote political army-building... and always dare to fight and win."