Japan Football Association (JFA) president Kuniya Daini said the country, whose capital Tokyo will stage the 2020 Olympics, would step in if required.

"If FIFA look for an alternative country, we already have the stadiums that would meet the criteria to host it," he said in an interview.

"We have the Olympics in 2020. If there is a chance, we'd like to do it, although I don't know how likely that would be."

The chance of Qatar losing hosting rights appears remote despite an investigation by FIFA's ethics committee, headed by former US district attorney Michael Garcia, into the much-criticised bidding process.

Qatar has also come under fire for its treatment of foreign construction workers, with figures obtained by AFP in February showing that 450 migrants from India alone had died over the past two years — about 20 a month.

And there is a row over whether to hold the Qatar World Cup in the intense heat of the desert summer or in winter, which is mid-season for many domestic leagues.

Japan, one of the countries that lost out to Qatar for the 2022 World Cup, has experience of organising the tournament after co-hosting the 2002 edition with Asian neighbours South Korea.

Japan reached the knock-out stages that year and again in 2010, and Daini said the team hopes to take another step forward by making the quarter-finals at this year's competition in Brazil.

"We are looking to perform better than we did the last time," said Daini at the JFA's Tokyo offices. "In South Africa we got to the last 16 so that means this time we want to reach the quarter-finals.

"That would be a successful result, but first we have to advance from the group stage. It's a difficult group, so that's the first aim."

- Asia's best chance in Brazil -

Daini said Japan also hoped to bring back the Club World Cup, which it has hosted six times before, and hold the 2023 Women's World Cup.

At this year's World Cup, Japan are considered as Asia's best chance with a squad that boasts Manchester United's Shinji Kagawa, Keisuke Honda of AC Milan and Yuto Nagatomo of Inter Milan.

Daini said nothing had been decided about the future of Italian manager Alberto Zaccheroni, who will attempt to steer Japan through Group C against Colombia, Greece and Ivory Coast.

"We haven't decided anything regarding the manager's future yet. When the World Cup is over we will analyse everything and think about what kind of team we need to build for the next World Cup," he said. "When we know that, we'll know what kind of manager we need."

Daini also admitted he was shocked after a racist "Japanese only" banner targeting foreign fans was unfurled at Urawa Red Diamonds' Saitama Stadium.

The incident prompted the J-League to take the unprecedented step of forcing Urawa to play their next home game behind closed doors.

"After the Urawa incident I thought, 'So something like this has finally happened in Japan'," Daini said. "I thought that nothing like this could happen in Japan, so it was a shock.

"Japanese football and the J-League are known for being a safe environment with lots of women and children attending games, so this has created a dangerous image and lowered the prestige of Japanese football."

And he said unproven match-fixing suspicions, following unusual betting patterns on a March 8 game between Sanfrecce Hiroshima and Kawasaki Frontale, were a wake-up call for Japanese football.

"With regards to the match-fixing suspicions, it was a good warning for if something were to happen for real. We all thought that something like this couldn't happen in Japan, but it showed us that it is possible and for that reason it was very effective," he said.

Japan's J-League has so far remained largely untouched by match-fixing scandals that have hit several neighbouring leagues. A J-League probe into the recent game found no evidence to indicate match-fixing.