Dong replaces Li Shangfu, who was fired and disappeared from public view four months ago.
China has appointed former navy chief Dong Jun as the new defence minister after months of uncertainty following the sacking of his predecessor for still unknown reasons.
The official removal of Li Shangfu, the former defence minister, was only announced in October. Li has not been seen in public since late August.
Announcing Dong’s appointment on Friday at a meeting of the standing committee of China’s National People’s Congress, the state-run Xinhua news agency did not provide any reasons for the change or Li’s current whereabouts.
Dong, 62, takes over the largely ceremonial role at a time when the United States has ramped up its efforts to bolster diplomatic and defence ties in the Asia Pacific as part of a campaign to compete with China.
While Dong will be the public face of the People’s Liberation Army (PLA) in its engagement with the media and with other militaries, his ministry will have little say in defence policy or military management.
Those critical areas fall under the purview of the Central Military Commission, an elite group that is led by President Xi Jinping.
An important element of his role will be to engage with the US military to lower the risk of conflict over Taiwan and the South China Sea.
China has increased military pressure on the democratically governed island of Taiwan, which it claims in its entirety, in advance of presidential and parliamentary elections next month.
Before becoming the PLA’s navy chief and being made a full general in 2021, Dong was vice commander of the East Sea Fleet, the backbone of what is now the Eastern Theatre Command – the main force responsible for fighting over Taiwan.
He also served as vice commander of the Southern Theatre Command which operates in the disputed South China Sea – which is claimed by China, much to the ire of neighbouring Philippines, Vietnam, Taiwan, Brunei and Malaysia.
Li became defence minister in March and was seen as a Xi loyalist. Speculation over the reason for his ouster, and that of Foreign Minister Qin Gang in July, has ranged from corruption allegations to spying suspicions.
The US imposed sanctions on Li in 2018 over weapons purchases from Russia, including Su-35 combat aircraft and S-400 surface-to-air missile systems.
Fighting alleged corruption has long been a central theme of Xi’s rule.
China’s opaque political and legal systems and the lack of information related to the removals of the defence and foreign ministers, have led some to question whether they were due to corruption or disputes with influential figures.
Last year, former Industry Minister Xiao Yaqing vanished from public view for nearly a month before it was revealed he was being investigated for corruption.
Recent months have also seen an overhaul in the leadership of China’s secretive Rocket Force, the army unit that oversees Beijing’s nuclear arsenal, following media reports of a corruption probe involving its former chief.