Japan proposed on Thursday expanding emergency restrictions to eight more prefectures to fight a surge in COVID-19 cases, a cabinet minister said, as worries grow about strains on the nation's medical system in Olympics host Tokyo and elsewhere.

Economy Minister Yasutoshi Nishimura, who is leading Japan's pandemic response, made the proposal at a meeting of experts, who were expected to sign off. Six prefectures including Olympic host city Tokyo are already under full states of emergency to last through August 31 while another five are under less strict "quasi-emergency" directives.