China named Dong Jun as its new defence minister on Friday to replace the last minister who disappeared four months ago.

The appointment by Chinese lawmakers comes as President Xi Jinping upgrades the military as part of his push to make China a dominant world power, a goal that has alarmed many neighbours.

The role of China’s defence minister is to be the public face of the People’s Liberation Army in its engagement with the media and with other militaries. Dong, 62, was most recently the PLA’s naval chief. He replaces Li Shangfu, who took up the defence minister job in March but had not been seen in public since August 25.

Reuters cited sources to report that Li was under investigation for corruption related to equipment procurement and development.

Beijing has not explained Li’s disappearance but stripped him of his title as defence minister and state councillor in October. A crucial element of China’s defence minister job is to engage with the US military to lower the risk of conflict over Taiwan and the South China Sea.

Yet during his brief tenure as minister, Li did not meet his US counterpart — defence secretary Lloyd Austin. The ministry explained that Washington would have to first remove the sanctions it placed on Li on 2018 over his role in purchasing Russian aircraft and equipment.