BEIJING--This week’s global climate talks in Scotland and the recent G-20 summit in Rome aren’t the only international meetings that China’s leader has not attended in person. Xi Jinping hasn’t left China in nearly 22 months, since January 2020 when the COVID-19 pandemic first exploded.

His absence drew criticism from U.S. President Joe Biden and questions about China’s commitment to reducing greenhouse gas emissions. China, the world’s biggest emitter, has pledged to begin reducing its output by 2030 and reach carbon neutrality by 2060. The U.S. and others have urged China to advance those goals, but it has balked so far.

“We made our promises and we honor our promises with actions,” China climate envoy Xie Zhenhua said in Glasgow, blaming America’s now-reversed withdrawal from the Paris climate accord under former President Donald Trump for a “wasted five years” in tackling climate change.

China may not be ready to offer any new initiatives on climate, but Xi’s non-appearance also reflects the ruling Communist Party’s zero tolerance approach to controlling the coronavirus. After being the first country overwhelmed with the disease in early 2019, it has stamped out its reappearances with strict lockdowns, quarantines and travel restrictions.

The government has gone to great lengths to protect Xi and other leaders from COVID-19. He has met other world leaders and attended global meetings, but only by video link from China. Xi doesn’t normally give news conferences, but other leaders such as Premier Li Keqiang have met with the media only by video, and even then, journalists have had to test negative for COVID-19 to participate remotely.

Xi last left China in January 2020 for a trip to neighboring Myanmar. That was shortly before the outbreak, first detected in the Chinese city of Wuhan, started to spread widely worldwide. China has come under pressure from the U.S. and others to reveal more information about the origin of the pandemic and has been accused of mismanaging the initial outbreak and then seeking to cover up its mistakes.

The pandemic has given Xi a convenient excuse not to travel at a time when China faces heavy criticism of its policies toward Muslims in its Xinjiang region and its crackdown on individual rights in Hong Kong. Chinese leaders are extremely image conscious and Xi’s public appearances are carefully choreographed to avoid potentially embarrassing confrontations.

His current stay-at-home approach contrasts with a formerly heavy travel schedule that took him across continents as he tried to boost China’s international profile. First lady Peng Liyuan, an accomplished musician, was often on hand to add a bit of glamor and a human touch.

He met with the then-Japanese emperor in Tokyo, rode a gilded carriage with Britain’s Queen Elizabeth and paid a visit to North Korea’s capital that included a ride through city streets lined by tens of thousands of cheering citizens.

Such travels have underscored a more assertive foreign policy under Xi, as the world’s second-largest economy seeks to extend its influence beyond East Asia with his signature “Belt and Road” overseas infrastructure investment program.

Xi isn’t alone in skipping the meetings in Rome and Glasgow. Russian President Vladimir Putin, whose country has aligned with China in opposing U.S. influence in world affairs, also remained at home.

“I think it’s been a big mistake, quite frankly, for China, with respect to China not showing up,” Biden said Monday at the COP26 climate conference in Glasgow.

Responding to the U.S. president’s remarks, Chinese Foreign Ministry spokesperson Wang Wenbin said Wednesday that China’s response to climate change is concrete, pointing to recent achievements in reforestation and renewable energy.

Shi Yinhong, a professor of international relations at Renmin University in Beijing, said that friction in bilateral relations is complicating cooperation between the two countries on climate change.

Biden has taken the Glasgow climate meeting as “an important occasion for China and the U.S. to compete for global influence, ideology and image,” said Shi, who attributed Xi’s absence to China’s zero tolerance approach to dealing with the pandemic.

Xi has remained in contact with foreign heads of state through virtual meetings, said Zhao Kejin, who teaches international relations at Beijing’s Tsinghua University.

The U.S. wants Chinese cooperation in responding to climate change, but Beijing is looking for changes in U.S. policy, including its support for the self-governing island of Taiwan, which China claims as its own territory, Zhao said.

“This result was produced by the U.S. failing to integrate ties with China into its overall multilateral relationships,” Zhao said.

British Prime Minister Boris Johnson said Tuesday that Xi’s absence “doesn’t mean the Chinese are not engaging” in the fight against climate change but added that he wants China to do more to slash carbon emissions. He told reporters that China had made a substantial commitment and praised Beijing’s decision to end financing for overseas coal plants, though not yet at home.