Japan's government has said it plans to extend emergency Covid-19 restrictions in Tokyo and other regions in a bid to curb infections and prevent hospitals from being overwhelmed as it is still too early to let down its guard, reports Reuters.

Japan has been struggling with a fifth wave of the virus and last month extended its long-running curbs until September 12 to cover about 80 per cent of its population.

However, the number of severe cases and the strain on the medical system have not eased sufficiently in Tokyo and surrounding areas to allow the restrictions to be lifted.

The government will seek to extend the measures until September 30, including for the capital Tokyo and the second city of Osaka, Economic Minister Yasutoshi Nishimura told a government meeting. The plans must be ratified by a panel of experts and others.