China on Friday reiterated its call to make COVID-19 vaccines accessible and affordable in developing countries, describing vaccines as a "powerful weapon" to defeat the pandemic and revive the global economy. China has provided more than 500 million doses of vaccines to other developing countries and will provide another $3 billion in international aid over the next three years to support COVID-19 response and economic and social recovery in other developing countries, Chinese President Xi Jinping said while addressing the Informal Economic Leaders' Retreat of the Asia-Pacific Economic Cooperation (APEC) via video link.