Tokyo has a civic duty to dust itself down from the failed 2016 Olympic bid and reapply to host the 2020 Games, the city's governor said yesterday.

The Japanese capital lost out to Rio de Janeiro in last month's 2016 vote but Shintaro Ishihara insisted Tokyo had the motivation and funds to try again.

"We did spend money on the (2016) bid but we have the finances set aside for such big projects," Ishihara said.

"Tokyo lost out for the 1960 Olympics before winning the rights to host the 1964 Games. It is necessary to examine why our bid failed and see what we need to do to be successful.

"It's important for Tokyo to leave a legacy for future generations. I will address the city assembly about applying for 2020 and ask them to decide."

Tokyo secured a contingency fund of $4 billion for the 2016 Games but Japanese Olympic officials were said to have favoured a bid for 2020 from the start.

"While Tokyo and Fukuoka were contesting the right to be Japan's bid city I said we should reapply if Tokyo did not win the 2016 vote," the 77-year-old Ishihara said.

"For now we have to submit the necessary paperwork in line with the IOC's (International Olympic Committee) deadlines."

Hiroshima and Nagasaki, the only cities to have suffered a nuclear attack, have expressed an interest in tabling a joint-bid for the 2020 Olympics.

The mayors of both cities met in Osaka yesterday to ask Japan's second city for its help in examining the logistics of their proposal.

JOC executive board member Koji Kimura told reporters Japan's national committee would choose Japan's 2020 bid city "by next summer".

Rio won the Oct. 2 IOC vote for 2016, defeating Chicago, Madrid and Tokyo, Asia's first Olympic host city 45 years ago.

London hosts the 2012 Summer Games.