Confirmed coronavirus cases in Tokyo hit a new daily record with 286 on Thursday, a day after the Japanese capital raised its COVID-19 alert to the highest level.

The surge in cases has also heightened Japanese officials' concerns over the United States' handling of outbreaks at its military bases in the country, as well as fueling doubts over an upcoming campaign to boost tourism.

Tokyo Governor Yuriko Koike said the sharp rise in confirmed cases comes as more tests have been conducted, now over 4,000 a day. "We will respond appropriately to reduce the number of people being infected," she told reporters.

'Go To' campaign

As cases soar in Japan, including 136 reported at the US military facilities in the country, many have begun questioning the US military's policy in response to the coronavirus. That also goes for the multibillion-dollar campaign to boost domestic tourism known as "Go To".

On Wednesday, Japanese Defense Minister Taro Kono revealed that three people linked to a US base in Yamaguchi Prefecture who tested positive for the virus had lied about their travel plans after entering the country.

The three family members, who flew to Tokyo's Haneda Airport from the US on Sunday, told authorities that they would rent a car for their journey to US Marine Corps Air Station Iwakuni after taking polymerase chain reaction tests at the airport. However, they took a commercial flight to Iwakuni Kintaikyo Airport on Monday before the test results became available.

"It's an extremely disappointing situation," Kono said. "We have requested the US side dole out a strict punishment and prevent a recurrence of this."

The Yamaguchi prefectural government also said it was checking those who had close contact with the family.

As for the "Go To" campaign, Japanese Chief Cabinet Secretary Yoshihide Suga said on Thursday that there was no change in the launch plans, despite the growing calls for a review.

"We hope the 'Go To' campaign supports tourism and the food and beverage industry and brings about a social and economic recovery so that the regions can escape this severe situation."

Scheduled to begin on July 22, the campaign plans to initially provide discounts worth 35 percent of a tourist's total costs with a further 15 percent to be issued after September.

Agencies contributed to the story.