China’s Foreign Minister, Qin Gang has not been seen in public for three weeks, an unusually long absence during a busy period of diplomatic activity in Beijing, sparking intense speculation in a country known for its political opaqueness.

Qin, 57, a career diplomat and trusted aide of Chinese leader Xi Jinping, was promoted to foreign minister in December, after a brief stint as ambassador to the United States.

As foreign minister, Qin has delivered searing rebukes of Washington after relations plunged to a new low in the aftermath of a suspected Chinese spy balloon that was shot down over the US.

He has also played a key role in subsequent efforts by both sides to stabilize rocky ties and restore communication, including meeting with US Secretary of State Antony Blinken during his visit to Beijing in mid-June.

But the high-profile diplomat has not been seen in public since June 25, after he met with officials from Sri Lanka, Vietnam and Russia in Beijing.

In his last public appearance, a smiling Qin was seen walking side by side with Russian Deputy Foreign Minister Andrey Rudenko, who flew to Beijing to meet with Chinese officials after a short-lived insurrection by the Wagner mercenary group in Russia.

 “Given China’s status and influence in the world, it’s indeed very strange that its foreign minister has not appeared in public for more than 20 days,” said Deng Yuwen, a former editor of a Communist Party newspaper who now lives in the US.

When asked about Qin’s prolonged absence at a press briefing Monday, a Chinese Foreign Ministry spokesman said she had “no information to provide,” adding that China’s diplomatic activities are being carried out as usual.

Qin’s absence was made all the more conspicuous by the flurry of diplomatic activity in the Chinese capital in recent weeks, including high-profile visits by senior US officials Janet Yellen and John Kerry.

Qin was supposed to meet European Union foreign policy chief Josep Borrell earlier this month in Beijing but the meeting was pushed back after China informed the EU that the dates were “no longer possible,” Reuters reported, citing an EU spokesperson.

The EU was informed of the postponement just two days before Borrell’s scheduled arrival on July 5, according to Reuters.

Qin also failed to show up at an annual foreign ministers’ meeting of the Association of Southeast Asian Nations (ASEAN) in Indonesia last week. Instead, China’s top diplomat Wang Yi attended the gathering in his place.

A spokesperson for the Chinese Foreign Ministry told a regular news briefing last Tuesday that Qin could not attend the ASEAN meeting “because of health reasons,” according to Reuters.

But that response was missing from the briefing’s official transcript posted later on the ministry’s website. The Chinese Foreign Ministry often leaves out content it deems sensitive from the transcripts of its regular briefings.

The brief health reason cited by authorities, however, has failed to quell a groundswell of largely unsubstantiated speculation as to why Qin has not been seen.

These rumors are driven by a lack of transparency in the Chinese political system, in which information is closely guarded and important decisions are mostly made behind closed doors, said Deng, the US-based analyst.

Under Xi, this political opacity has only intensified, as he cracks down on dissent and concentrates power in his own hands.

“This is a problem for totalitarian regimes. Totalitarian regimes are inherently unstable because everything is decided by the supreme leader alone,” he said.

“If anything unusual happened to a senior official, people will wonder if their relations with the top leader have soured or whether it is a sign of political instability,” said Deng.

Senior Chinese officials have disappeared from public view in the past, only to be revealed months later by the ruling Communist Party’s disciplinary watchdog that they’ve been detained for investigations. Such sudden disappearances have become a common feature in Xi’s anti-corruption campaign.

Adding to the sensitivity of Qin’s absence is his perceived close ties to Xi, who secured a norm-breaking third term in power last autumn with a new leadership team stacked with loyal allies, according to Deng.

“Qin Gang was single-handedly pulled up the ranks by Xi. Any problems with him will reflect badly on Xi too – implying that Xi failed to choose the right person for the job,” said Deng.