Tokyo and Doha submitted bids Monday to host the 2020 Olympics, delivering their files to the IOC two days before the deadline.

Delegations from both cities turned in documents to International Olympic Committee headquarters, the first of the six candidate cities to do so. The other four 2020 contenders are Madrid, Istanbul, Rome and Baku, Azerbaijan.

The files must be submitted by the end of Wednesday.

The IOC will decide in May whether to retain all the candidates or pare the list. The IOC will select the 2020 host city at a meeting in Buenos Aires, Argentina, in September 2013.

A question mark still hangs over the Rome bid, which needs the support of the government amid Italy's financial crisis. Premier Mario Monti is to announce his decision Tuesday after a meeting with Rome Mayor Gianni Alemanno and other bid leaders.

Tokyo, which hosted the 1964 Olympics, is bidding for a second consecutive time after an unsuccessful attempt for the 2016 Games, which were awarded to Rio de Janeiro. Tokyo said its bid file included a letter of guarantee signed by Prime Minister Yoshihiko Noda.

"We have learned valuable lessons from our previous bid, which are evident from these improved technical plans," Tsunekazu Takeda, president of the Tokyo bid, said in a statement.

Doha also bid for the 2016 Games, but failed to make the shortlist of finalists. The Gulf city is seeking to bring the games to the Middle East for the first time. Qatar will be hosting the 2022 World Cup.

Doha proposes holding the Olympics in September or October to avoid the summer heat, which can exceed 104 degrees in July.

Doha's delegation was led by bid vice chairman Sheik Saoud bin Abdulrahman Al Thani and included two female athletes. Qatar has never sent a woman to the Olympics but hopes to include women on the team for this summer's London Games.

"Our applicant file contains a strong hosting plan that is based on many existing venues and a number of planned facilities," Al Thani said. "2020 is an historic opportunity to grow the Olympic movement in a new region."

Madrid will submit its documents on Tuesday and Istanbul on Wednesday. The files can be made public starting Thursday.