President Joe Biden is set to meet virtually with Chinese leader Xi Jinping on Monday evening. It is the third major international meeting — G20 and the 2021 United Nations Climate Change Conference — Xi has declined to attend in-person and the 667th day since Xi last traveled outside of China.

Xi has nominally remained inside China’s borders in keeping with the country’s relatively drastic efforts to eliminate COVID-19. Nevertheless, Chinese relations with the world appear to be taking a hit in his absence, with the country losing much of the diplomatic ground it may have gained under former President Donald Trump’s arguably hands-off approach to global politics. Xi has attempted to pick up the slack by holding a plethora of calls with world leaders, including Angela Merkel of Germany, Vladimir Putin of Russia, Emmanuel Macron of France and Biden.

Xi may fear the optics of traveling internationally on a regular basis even as Chinese citizens face harsh crackdowns for small outbreaks. Beijing itself has also been off-limits for even the most senior foreign envoys since the pandemic began, according to Bloomberg News. U.S. climate envoy John Kerry met with Chinese officials in Tianjin, a smaller city outside the capital.

But while COVID-19 optics present a plausible reason for Xi’s stagnancy, some have suggested the true reason is ongoing political unrest within the Chinese Communist Party (CCP). While Xi removed the two-term limit on Chinese leaders, he still needs the support of the CCP to be re-upped for leadership every five years. He is next due for approval in October 2022, placing him in the opening days of what Americans might call an election season. (RELATED: Biden Administration Announces Changes To Get China To Comply With Trump-Era Trade Agreement)

Evidence of unrest within the CCP has come in trickles but is mounting. In October, Xi’s administration announced an investigation against Fu Zhenghua, a top-level CCP official who for years was seen as one of Xi’s closest allies. Fu led the country’s justice ministry and served as deputy police chief for several years under Xi’s leadership, going so far as to remove one of Xi’s top political opponents in 2013.

There have also been rumblings of a foiled plot against Xi by CCP members in October. Two articles published to non-state run outlets NetEase and Sohu reported that there had been an attempted plot to move against Xi during a scheduled visit to Nanjing. The articles were removed from the sites within 24 hours. The alleged effort was reportedly financed by the estate of a billionaire the CCP had executed for bribery in January, Lai Xiaomin, according to the Sydney Morning Herald.

“It seems very credible because the two media outlets – NetEase and Sohu.com – are not party mouthpieces, but I would describe them as semi-official,” Dr. Willy Wo-Lap Lam, an expert in elite Chinese politics at the University of Hong Kong, told the Herald. “They are widely read and have been tolerated by the Propaganda Department for at least 20 years.”

Reports of unrest within China’s leadership paint Xi’s refusal to leave the country in a different light. Biden is likely to focus on climate change during his Monday evening meeting with Xi. It remains the Biden administration’s official position that China is carrying out a genocide against Uyghur Muslims in Xinjiang.