TOKYO, Aug 5 (Reuters) - 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.

Officials have warned that coronavirus infections were surging at an unprecedented pace as new cases hit record highs in Tokyo, overshadowing the Olympics and adding to doubts over the government's handling of the pandemic.

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 Aug. 31 while another five are under less strict "quasi-emergency" directives. (Reporting by Linda Sieg and Ami Miyazaki; Editing by Muralikumar Anantharaman)