In a response to a question in Japan's parliament, Seiko Hashimoto said Tokyo's contract with the International Olympic Committee (IOC) "calls for the Games to be held within 2020".

She added that "could be interpreted as allowing a postponement".

The Games are due to be held from 24 July to 9 August.

"We are doing all we can to ensure that the Games go ahead as planned," Hashimoto added.

Under the hosting agreement the right to cancel the Games remains with the IOC.

IOC president Thomas Bach says his organisation remains "very confident with regard the success" of the Games in Tokyo.

"I would like to encourage all the athletes to continue their preparations with great confidence and full steam," added the German.

A number of high-profile sporting events have already been cancelled or postponed as a result of the coronavirus outbreak, including the World Athletics Indoor Athletics Championships and the Chinese Grand Prix, which was scheduled for 19 April.

Coronavirus, which originated in China, has spread to more than 60 countries and claimed more than 3,000 lives so far.

The IOC executive board met in Lausanne, Switzerland on Tuesday and in a statement "expressed its full commitment to the success of the Olympic Games Tokyo 2020 taking place from 24 July to 9 August".

It said a "joint task force" was started in mid-February, involving the IOC, Tokyo 2020 organisers, the host city of Tokyo, the government of Japan and the World Health Organization.

The executive board added that it "appreciates and supports the measures being taken, which constitute an important part of Tokyo's plans to host safe and secure Games".

"We will continue to support the athletes and their NOCs with regular updates of information, which we will provide," Bach added