Japan confirmed more than 80,000 daily coronavirus cases on Friday, setting a new record for the fourth consecutive day, as the highly transmissible Omicron variant continues to wreak havoc across the country.

The nationwide tally reached 81,822, with Tokyo, Osaka and more than 20 other prefectures reporting record daily counts. The capital confirmed 17,631 cases and Osaka recorded 10,013 cases, topping 10,000 for the first time.

Japan started seeing an explosive increase in daily COVID-19 cases about a month ago when there were only around 500 cases a day.

"It is difficult to say whether (the virus spread) will pass a peak in a matter of one week or two" despite the slowing pace of increase in new cases in most parts of the country, Shigeru Omi, the government's top COVID-19 adviser, told a parliament session Friday.

The number of COVID-19 patients with severe symptoms stood at 697 on Friday, up 160 from the previous day, the health ministry said.

According to a survey by the National Institute of Infectious Diseases of 122 people who were admitted to hospitals and confirmed to be infected with the Omicron variant of coronavirus, 63 percent of them had already been vaccinated twice against COVID-19, substantiating recent studies showing vaccine-induced immunity wanes over time.

Currently, 34 out of the country's 47 prefectures have been placed under a quasi-state of emergency that allows local authorities to ask restaurants and bars to shorten their business hours and limit or stop the serving of alcohol.

The rapid spread of the variant is putting pressure on the health care system and other areas of society. As such, Japan will further shorten the quarantine period to seven days from the current 10 for people who have been in close contact with someone infected with the novel coronavirus, Prime Minister Fumio Kishida said Friday.