The leaders of Japan, the United States, Australia and India agreed Friday to work to expand COVID-19 vaccine production for developing countries amid China's growing influence, while pursuing collaboration toward a rules-based maritime order in disputed waters.

India will not allow the export of the Oxford University-AstraZeneca coronavirus vaccine for several months, the head of Serum Institute of India, which has been contracted to make 1 billion doses of the vaccine for developing nations, said Sunday.