The trip, scheduled "in the coming days," will be the highest level visit by any US Cabinet official to the island since 1979, when Washington broke official ties with Taiwan to establish diplomatic relations with Beijing, said a statement from the US Health and Human Services (HHS) Department.
The high-profile trip is likely to worsen relations between Beijing-Washington, which have nosedived this year to their lowest point in decades. For years, tensions and rivalries have simmered between the world's two largest economies over trade, technology and geopolitics, but the coronavirus pandemic has dealt a further blow to their already strained ties.
During his visit, Azar will meet with senior Taiwan counterparts, Covid-19 responders and experts on behalf of US President Donald Trump to discuss the global pandemic response, US-Taiwan partnership and the island's role as a "reliable global supplier of medical equipment and critical technology," according to the statement.
"Taiwan has been a model of transparency and cooperation in global health during the Covid-19 pandemic and long before it," Azar said in a statement.
"I look forward to conveying President Trump's support for Taiwan's global health leadership and underscoring our shared belief that free and democratic societies are the best model for protecting and promoting health," he said.
Taiwan's Foreign Ministry said the visit would be a "testament to the solid mutual trust and smooth communication between Taiwan and the US" and the "close partnership the two nations share."
The United States does not maintain formal diplomatic ties with Taiwan, however, it remains a firm backer of the island and its primary arms supplier.
The last time a US Cabinet official had visited Taiwan was six years ago, when Former President Barack Obama sent Environmental Protection Agency Administrator Gina McCarthy to the island in 2014. That visit prompted a fierce protest from Beijing, with its foreign ministry expressing "resolute opposition and strong dissatisfaction."
Growing tensions
During the pandemic, US and Taiwan have also forged closer ties in the area of public health.
In April, Azar spoke to his Taiwanese counterpart Chen Shih-chung about fighting the coronavirus outbreak, thanking him for "Taiwan's efforts to share their best practices and resources with the US," Azar said on Twitter at the time.
The US also led a diplomatic campaign to restore Taiwan's observer status in the World Health Assembly (WHA), an annual meeting of World Health Organization (WHO) members. Led by the US, a group of eight countries including Japan, the UK and Australia, issued a joint letter calling for Taiwan's inclusion in the WHA, a move that drew the ire of Beijing.
Since Taiwan President Tsai Ing-wen took office in 2016, Beijing has blocked the island from attending the WHA as part of a wider push to isolate it on the international stage, as cross-strait relations deteriorated.
China's ruling Communist Party considers the self-ruled democracy as an integral part of its territory to be taken by force if necessary, despite having never controlled Taiwan.
Beijing blames Tsai's the pro-independence Democratic Progressive Party (DPP) for Taiwan's exclusion from the WHA.
"Since DPP took office in 2016, it has been insisting on the so-called 'Taiwan Independence' and refusing to recognize the fact that both the mainland and Taiwan belong to China," Chinese Foreign Ministry spokesperson Zhao Lijian said ahead of the WHA meeting in May.
"The purpose of certain countries' discussion of Taiwan-related proposals is to seriously interfere with the agenda of the WHA and undermine international cooperation in fighting the Covid-19 pandemic," Zhao said.
In the end, Taiwan was again excluded from this year's WHA, over which the US expressed its "deep disappointment."
"WHO barred Taiwan from participation in 2016 just a few months after Taiwan's free and fair elections. The health of 23 million Taiwanese people should never be sacrificed to send a political message," he said.
In its statement Wednesday, Taiwan's Foreign Ministry called Azar an "unwavering friend of Taiwan" for his firm support of Taiwan's inclusion in the WHO and related events.