TAIPEI, Taiwan — They are sending millions of masks, emblazoned with the words “made in Taiwan,” to the United States, Italy and other countries hit hard by the coronavirus. They are denouncing Taiwan’s exclusion from the World Health Organization. They are flaunting celebrity endorsements and creating hashtags like #TaiwanCanHelp.

Officials in Taiwan are attempting to turn their success in battling the coronavirus at home into a geopolitical win. Taiwan is competing with China on pandemic aid diplomacy in defiance of Beijing’s efforts to isolate the self-ruled democratic island that it claims as its own. The island is promoting itself as a model of democracy to try to undercut China’s own campaign to use the crisis to tout the strength of its authoritarian system.

“We can see that this is a good opportunity for us to let people know that Taiwan is a good global citizen,” Taiwan’s vice president, Chen Chien-jen, said this week in an interview in Taipei. “We have to fight for our participation.”

Taiwan’s push for greater global recognition has in large part been an effort to raise questions about the cost of China’s campaign to isolate the island diplomatically. China has worked to shut Taiwan out of groups like the World Health Organization, a U.N. agency, denying it access to scientific briefings and emergency meetings.

Mr. Chen, the vice president, said that Taiwan had been “left as an orphan” because of China.

“No country can fight Covid-19 alone,” said Mr. Chen, an epidemiologist by training. He said the island wanted “a chance to share our knowledge and experience and our technologies with other countries.”

While Taiwan’s push for a greater voice in the health agency has drawn supportive comments from officials in the United States, Japan, Canada and elsewhere, experts say it is unlikely to result in any immediate breakthroughs. The W.H.O. has said that the question of Taiwan’s membership in the agency is up to member states, not the W.H.O.’s leaders, and that it has allowed Taiwan to participate in trainings and research conferences related to the virus.

The debate over Taiwan’s exclusion has at times been heated.

The director-general of the W.H.O., Dr. Tedros Adhanom Ghebreyesus, facing criticism from the Trump administration and others that he is too deferential to China, has accused Taiwan of unleashing racist attacks against him online. Taiwan’s president, Tsai Ing-wen, has rejected Dr. Tedros’s claims and her government has said that the online attacks were coordinated by Beijing.

The island wants to push a simple message: “Taiwan Can Help.” But underlying it is a multifaceted effort to challenge Beijing in the realm of coronavirus aid diplomacy.

More broadly, Taiwan has tapped into rising concerns around the world about the costs of the Chinese Communist Party’s penchant for secrecy. In contrast, Taiwan has presented its government as one that exudes confidence as it welcomes civic participation and the scrutiny of the press.

Even Ms. Tsai, the president, has adopted a more public diplomatic strategy, casting aside her usual approach of working behind the scenes in reaching out to foreign leaders.

Beijing has shown no signs of easing its aggression toward Taiwan, despite the pandemic, sending warships into the waters off its coast. Some commentators in China have threatened economic punishment if the island continues making diplomatic overtures.

Chinese officials have accused Taiwan of working to “make reckless political maneuvers and hype up” its participation in global organizations. “Their scheme will never succeed,” Zhao Lijian, a spokesman for the Chinese foreign ministry, said this month at a news conference in Beijing.

Now some in Taiwan worry that Beijing might more severely restrict trade with the island.

“Politically, we want to keep a distance. But economically it’s very difficult,” said Alex Chiang, a retired professor of diplomacy at National Chengchi University in Taipei. “After the Covid crisis is cover, we still have to go to China and cooperate with Chinese businesspeople in order to get economic recovery started.”

Mainland analysts argue that Taiwan’s moves to assert itself will worsen tensions between China and the United States. China is already upset that President Trump last month signed legislation aimed at discouraging Taiwan’s few remaining diplomatic allies from cutting ties with the island under pressure from Beijing.

“This will increase conflicts or even confrontations between China and U.S.,” said Zhang Wensheng, associate dean at the Taiwan Research Institute at Xiamen University in eastern China.

Taiwan’s citizens say they are trying to ignore the mainland’s threats.

Many have in recent days joined the effort to raise the island’s profile, helping spread hashtags like #TaiwanCanHelp and organizing crowdfunding campaigns to buy advertisements in Western news outlets highlighting the island’s successes.

Albee Zhang contributed research.