TOKYO (REUTERS) - Japan's capital Tokyo said on Thursday (Dec 17) the strain on its medical system from the Covid-19 pandemic was severe, raising its alert level to the highest of four stages as the number of cases spiked to a record daily high of 822.

A health official said it had become difficult to balance the care of Covid-19 patients with regular ones as hospital beds filled up, assigning a "red" alert for medical preparedness for the first time.

"Medical service providers have exhausted all spare resources," Dr Masataka Inokuchi, vice-chair of the Tokyo Medical Association, told a coronavirus monitoring committee meeting attended by Tokyo Governor Yuriko Koike.

"Reducing the number of (Covid-19) patients will be the only way to go."

The metropolitan government said the number of coronavirus cases hit 822 on Thursday, surpassing the previous record of 678 reached a day earlier.

A month ago, the city raised its coronavirus alert for new infections - a separate category - to the highest level.

It had kept its alert for medical preparedness at the second-highest level at the time, indicating a need to boost hospital capacity but a notch below critical conditions.