Taiwan is battling a spike in domestic infections and has vaccinated only around 3% of its population. Japan has contracted to procure more than 300 million doses of coronavirus vaccines from Pfizer Inc, Moderna Inc and AstraZeneca, more than enough to cover its entire population. "At the time of the great east Japan earthquake 10 years ago, people in Taiwan sent us a lot of donations promptly. I believe that is etched vividly in the minds of Japanese people," Motegi said, announcing the vaccines would reach Taiwan on Friday afternoon.

"Such an important partnership and friendship with Taiwan is reflected in this offer." Taiwan thanked its former colonial master for its generosity.

"The relationship between Taiwan and Japan has always been extremely close, and our friendship is firm and deep," Taiwan's Foreign Ministry said. "Whenever disasters or accidents occur, both sides immediately lend a helping hand to each other and send help in the hour of need." The donation is a triumph for Taiwan President Tsai Ing-wen, who has faced public anger about the slow arrival of vaccines and small protests by the main opposition party the Kuomintang outside her offices.

The donation "reflects the results of close exchanges between the Tsai Ing-wen government and the Japanese government over the past five years", Taiwan's ruling Democratic Progressive Party said. Though Taiwan's share has not been announced, the island will also be receiving shots under a White House plan for United States to share 25 million surplus COVID-19 vaccine doses to the world.

Taiwan has received only around 860,000 doses so far, mainly AstraZeneca ones but also a smaller number from Moderna. It has ordered more than 20 million doses from AstraZeneca and Moderna and is also developing its own vaccines. Like many governments, Taiwan's vaccine plans have been stymied by global shortages.

China, which claims the island as its own territory, has offered vaccines, but Taiwan has repeatedly expressed concern about their safety, and accused China of trying to block Taiwan's vaccine purchases internationally. Beijing denies this. Japan approved AstraZeneca's vaccine last month and has contracted to buy 120 million doses. But there are no immediate plans to use the shots, amid lingering concerns raised internationally over blood clots.