Leaders from 21 Pacific-Rim economies including Japan, the United States and China pledged on Friday to beef up the availability of COVID-19 vaccines to tackle the coronavirus pandemic and to provide the necessary ongoing support for their economies to recover.

The leaders, struggling to tame outbreaks exacerbated by the delta variant of coronavirus, said they would encourage the voluntary transfer of vaccine production technologies "on mutually agreed terms" as the region prepared for future health shocks.

"We will only overcome this health emergency by accelerating equitable access to safe, effective, quality-assured and affordable COVID-19 vaccines," the leaders of the Asia-Pacific Economic Cooperation forum said in a statement issued after their informal virtual summit.