Originally Published: 18 JUN 21 05:45 ET

Updated: 18 JUN 21 08:30 ET

By Emiko Jozuka, Akanksha Sharma and Chie Kobayashi, CNN

(CNN) -- Japan's top coronavirus adviser said Friday that staging the Tokyo Olympics without spectators is "desirable" as it would be the lowest risk option amid the pandemic.

Shigeru Omi, an infectious disease expert who leads the government subcommittee on coronavirus, and other specialists urged the cap on spectator numbers at the Games to be stricter than the upper limit in place currently for large-scale events in Japan after submitting a report containing a set of proposals to the Olympic organizing committee.

The submission came a day after Prime Minister Yoshihide Suga decided to end the Covid-19 state of emergency in Tokyo and eight other prefectures on June 20.

Tokyo and six other prefectures will then shift to a quasi-state of emergency until July 11, except for Okayama and Hiroshima, where situations have improved enough to not require the designation.

Okinawa will remain under the current state of emergency until July 11 as the prefecture's hospitals are still under strain from Covid-19 patients.

At a Tokyo 2020 roundtable on Friday, organizing committee president Seiko Hashimoto said: "Yesterday, the Prime Minister made an announcement including the lifting of the state of emergency and the government's basic policy on holding events from now on. As we have been saying, the Tokyo Games will be managed under these government policies."

She added: "Earlier today, chairman Omi gave us his opinion about the risk of novel coronavirus infection in the Games. Based on Chairman Omi's proposal, I'd like you to actively discuss how to realize 'security and safety' from the expert's point of view."

Hashimoto told reporters later on Friday that organizers will try to accommodate spectators, but may have to cancel at the last minute.

Advice to spectators

Experts and officials also said on Friday that, as far as possible, any spectators at the Games should go straight to venues then straight home after watching events.

Hidemasa Nakamura, the Tokyo 2020 Games Delivery Officer, warned against celebrations involving alcohol on the streets amid the pandemic, saying that "drinking, or having a party on the street, it's not just a public nuisance, but it's a very negative event from an infection perspective as well."

Within venues, Nakamura urged spectators to "please keep a safe distance away from everyone except for your family members, and no group drinking and eating in the venue."

"So if you are eating, you need to eat alone or at least face the same direction as your friends and families", Nakamura added.

He also said that officials are looking at minimizing cross-prefecture travel to prevent any potential spread of Covid-19.

While the current rate of infection in Japan is declining, Tokyo 2020 senior officials have warned about the potential impact of the Covid-19 Delta variant.

Nakamura said that the Delta variant "may be a significantly big factor, potentially, in the near future," adding that athletes arriving from India, where the variant was first identified, will be required to quarantine upon arrival in Japan, as well as undergo testing every day for seven days before their arrival.