Tokyo will repay the world the debt they owe them for their help after the devastating tsunami in 2011 when the city hosts the 2020 Olympic Games Japanese Prime Minister Shinzo Abe said on Saturday.

The 58-year-old was speaking after the Japanese capital secured their second Olympic Games -- having previously had them in 1964 -- by beating Istanbul by 60 votes to 36 at a meeting of International Olympic Committee (IOC) members in Buenos Aires.

Abe, whose final presentation allayed members' fears over contaminated water leaking from the crippled Fukushima nuclear plant, said Japan would repay its debt to the world in full.

He added that he had seen how sport could change lives in the immediate aftermath of the quake and giant waves that struck northeast Japan in March 2011, leaving over 18,000 people dead and badly damaging the nuclear plant.

"Sport can mobilise people. That is the power shown exactly after the tsunami," he said.

"The situation was very tough but lots of athletes (including US sprint legend Carl Lewis) came to Japan and played with the kids and everybody had hope and courage.

"During the presentation I said about the boy I saw with a football given to him by one of these athletes. That football is not a gift. It is for the future. That is the power of sports.

"Japan needs hope and dreams and we are now looking forward to dreams and hopes. We will pay the debt of support we owe the world from the time of the tsunami."

Abe, who flew to South America from the G20 summit in St Petersburg, Russia, said the Olympics had given him such dreams when he was a boy in 1964 and was overwhelmed when he heard Tokyo announced as winners.

"I talked about the Olympic Games in 1964 then I was only 10 years old but a lot of kids were inspired like me by them and had dreams and hopes," he added.

"We wanted to have aspirations of winning a medal but for many it was not possible.

"When I heard Tokyo announced I was overwhelmed because I was the person that had got this medal and the joy was more than when I was first elected prime minister, the joy was greater."

Tokyo Governor Naoki Inose also said that hosting the Games would help Japan recover.

"By hosting the 2020 Tokyo Games, we will create hope," he said.

"We will offer dreams and hope to future generations and our hosting of the Games will accelerate the recovery of Japan's tsunami-affected area.

"We will promote the Olympic Movement globally in an effort to create a 'peaceful and better world'.

"Tokyo will be an environment where athletes can perform at their best, and we will offer guests from every corner of the world our excellent hospitality."

Japan's IOC member and Tokyo bid president Tsunekazu Takeda said the result was an enormous achievement after the city's failed effort to secure the 2016 Games, where they finished third.

The two-time showjumping Olympian said the trust placed in them would not be misplaced.

"The Olympic Family has put its faith in our great city to deliver the memorable Games we have promised and we will not let them down," said the 66-year-old.

"The most recent public polls revealed that 92 percent of the Japanese population supported Tokyo's hosting the Olympic and Paralympic Games, so I am confident that 116 million Japanese people are smiling right now."