The Olympics must not be a burden on regional medical systems, Japan's chief government spokesman said Friday, amid worries that daily athlete testing will tax health resources already stressed in fighting a rebound of COVID-19 cases.

The games will be held in a manner that makes everyone feel safe, Chief Cabinet Secretary Katsunobu Kato told reporters, responding to concerns raised by a nurses' union that the world's biggest sporting event will sap medical resources needed by the public.

Tokyo 2020 organizers this week issued the second edition of "playbooks" that lay out infection prevention standards for the Summer Games, which are due to start in less than three months after a one-year delay because of the pandemic.