Members of the media were given the chance to tour the 68,000-capacity stadium, which will be the centrepiece of Tokyo 2020.

According to news agency Reuters, National Stadium development director Takeo Takahashi said almost all the buildings had been finished and they were "now working on the interior and facility equipment inside the stadium".

"The grass and track have yet to be laid but this is expected to be completed in the next month," he added.

Around 45,000 seats have so far been installed at the stadium, being built at a cost of ¥149 billion (£1 billion/$1.3 billion/€1.1 billion).

An inauguration event is set to take place on December 21, Takahashi said, which will be open to the public.

It will give people the chance to have an inside look at the venue which will be the focal point of next year's Olympics and Paralympic Games and will hold the Opening and Closing Ceremonies, athletics and football.

The completion date was tentatively scheduled for November when Tokyo 2020 announced the capacities of all Olympic and Paralympic venues in March.

The stadium is designed by Kengo Kuma and is the second to be approved after initial plans were scrapped in 2015 by Prime Minister Shinzō Abe due to spiraling costs.

It features a roof with wood collected from all of Japan’s 47 prefectures.

The National Stadium is one of eight venues being constructed for next year's Games, which begin with the Opening Ceremony of the Olympics on July 24.