China removed Foreign Minister Qin Gang from his post on Tuesday after a one-month absence from public duties, replacing him with his predecessor Wang Yi, state media said, after weeks of speculation about what had happened to him.

Qin, 57, who only took up the job in December after a brief stint as envoy to the United States, had not been seen in public since June 25 when he met visiting diplomats in Beijing.

After he missed an international diplomatic summit in Indonesia, his ministry later said he was off work for unspecified health reasons, but the lack of detailed information fuelled a swirl of speculation.

It also deepened suspicion about transparency and decision-making among the country's cloistered leadership, analysts and diplomats said.

Wang, 69, who filled in for Qin during his absence, retakes the role he held between 2018 and 2022.

China's foreign ministry did not respond to a request for comment about reasons behind the switch.

It comes amid a flurry of international engagements and frayed ties with rival superpower the United States, which Beijing has described as at their lowest point since the establishment of diplomatic relations.

The world's two biggest economies are at odds over issues including Ukraine and Beijing's close ties to Moscow, trade and technology disputes, and Taiwan, the democratic, self-ruled island which Beijing claims as its own.