WASHINGTON, June 20 (CNN) - The United States is more than tripling its vaccine allocation to Taiwan, as the island battles a Covid-19 outbreak and resists pressure from Beijing to take China's homegrown inoculations.

Washington has shipped 2.5 million Covid-19 vaccine doses to Taipei, the US State Department spokesperson Ned Price tweeted on Saturday. The Moderna shots are set to arrive Sunday evening local time in Taiwan, according to the island's Ministry of Foreign Affairs.

After a wildly successful initial run of keeping case numbers down, Taiwan is now battling its first major outbreak and scrambling to combat its low vaccination rate: just 6 doses have been administered per 100,000 people.

China, which considers Taiwan an integral part of its territory, has repeatedly offered to send coronavirus vaccines to the island. Taipei has expressed concern about the safety of Chinese shots and accused Beijing of blocking its efforts to purchase vaccines internationally.

On June 6, the US pledged to donate 750,000 Covid-19 vaccine doses to Taiwan, which Taiwanese President Tsai Ing-Wen heralded as "timely rain" for the island of about 24 million people.

The US senators who visited Taiwan to make the announcement arrived on a US Air Force C-17 Globemaster III freighter. A primary strategic lift aircraft for the US military on a Taiwanese runway was seen as a major provocation of Beijing, as military tensions in the region heat up.

State-run nationalist tabloid Global Times said the move was "paving the way for the US and Taiwan to further escalate their collusion."
Taiwan was previously heralded as one of the world's success stories in controlling Covid-19 but has now reported nearly 14,000 cases and 538 deaths, according to the island's Centers for Disease Control.

After Saturday's announcement, President Tsai expressed her gratitude to the Biden administration and bipartisan US Congress support on her social media platforms.

"Thank you to the #US for this moving gesture of friendship. These vaccines will go a long way toward keeping #Taiwan safe & healthy," she tweeted.

Earlier this month, Biden announced that the US plans to donate 500 million Pfizer Covid-19 vaccine doses globally as part of his efforts to reassert US leadership on the world stage.