LONDON -- Less than three months before the IOC vote, Tokyo received the most praise Tuesday in a technical assessment of the three cities bidding for the 2020 Olympics.
The IOC evaluation report said Tokyo, Istanbul and Madrid all offer "high quality" bids and present their own "unique approach" to hosting the Summer Games.
The report touched on the financial crisis in Spain, saying Madrid's Olympic project was feasible despite the recession. The report was finalized in April and did not address the anti-government protests that have swept across Turkey recently and raised questions about Istanbul's bid.
Overall, Tokyo received the most glowing marks from the report, which described the Japanese capital as "a modern, dynamic city that sets global trends" and praised its compact venue plans and "one of the most modern and efficient public transport systems in the world."
The 110-page report, which is designed as a risk analysis, does not rank or grade the cities. But the document lays out strengths and weaknesses which are pored over closely by the candidate cities in the final stages of the race.
All three can take positives from the report, which was prepared for International Olympic Committee members ahead of a briefing by the bid cities next week in Lausanne, Switzerland.
The IOC will select the host city by secret ballot on Sept. 7 in Buenos Aires, Argentina.
Istanbul is bidding for a fifth time. Tokyo, which hosted the 1964 Olympics, is back for a second consecutive effort, and Madrid is trying for a third straight time.
The evaluation commission was chaired by IOC Vice President Craig Reedie of Britain. His panel visited each of the three cities in March.
"We are indeed very pleased with the quality of each bid and it is clear that the IOC members will have a difficult choice to make this September in Buenos Aires," Reedie said.
The report's influence on the race is uncertain. Not all IOC members read the evaluation reports carefully -- if at all -- and host-city votes are often driven by personal and geopolitical reasons more than technical issues.
The presentations to IOC members on July 3-4 are likely to be more crucial. It was at a similar briefing in 2009 where Rio de Janeiro, which did not rank highly in the technical report, seized the momentum in the race for the 2016 Olympics.
Tuesday's report said Tokyo's bid seeks to lift the nation's spirits following the devastating earthquake and tsunami that hit Japan in 2011. It said Tokyo had "well thought-out proposals" for ensuring "safe and secure games" and cited its $4.5 billion reserve fund -- money in the bank -- for financing Olympic construction.
The report did cite some concerns for Tokyo, including proposals to use three existing venues from the 1964 Games for judo, table tennis and boxing. It said the plan would "present operational challenges due to the limited space around the venues."
The IOC also raised concern over high hotel prices in Tokyo.
"We are proud that the report confirms our bid's very strong technical excellence, which offers certainty in uncertain times for sport," Tokyo bid leader and Japanese IOC member Tsunekazu Takeda said. "We are also aware that we must deliver much more than just a strong report."
Istanbul, which straddles Europe and Asia, is seeking to take the Olympics to a predominantly Muslim country for the first time. Istanbul would require the most spending and infrastructure work of the three cities, with a capital budget of $16.8 billion. The IOC report cited potential challenges with construction, traffic and other issues.
"Due to the estimated traffic growth the commission believes that the risk of road congestion during the games remains high, particularly in the coastal and Bosphorous zones," it said.
The report also noted that Turkey shares a border with Syria, which is currently engaged in a civil war that is driving refugees into Turkey.
"The conflict in Syria presents security risks, although the main effects appear to be in the southeast of the country," the IOC said.
Istanbul bid leader Hasan Arat said the report showed that the Turkish effort is "firmly on track."
"We know that we are at least on an equal footing with others in this race," he said.
The report was finalized on April 19 before the start of protests in Turkey, the biggest challenge to Prime Minister Recep Tayyip Erdogan's 10-year rule.
"The situation is now largely peaceful," Arat said in a conference call. "The violence that hijacked the peaceful protests has subsided."
Turkish Youth and Sports Minister Suat Kilic also downplayed the impact of the protests.
"The Turkish people and the people of Istanbul want the Olympics," he said. "The Turkish democracy is strong enough and experienced enough to surmount small societal incidents."
The IOC report noted that Istanbul would place emphasis "on the use of social media, particularly with regard to engaging young people." By contrast, Erdogan recently denounced Twitter -- and its use by protesters -- as "the worse menace in society."
Madrid's bid has a capital construction budget of only $1.9 billion, based on the use of 28 existing venues. The IOC praised Madrid's compact layout, short travel times for athletes and "vibrant festival" atmosphere.
Spain has been in recession for most of the past four years and has a 27.2 percent unemployment rate. While Madrid organizers "could still face some risks associated with the state of the Spanish economy," the IOC said the Spanish government reports the economy is showing signs of recovery.
"The commission believes that the degree of financial risk facing Madrid 2020 should be manageable over seven years within the Spanish economy and taking into account government guarantees," the IOC report said.
Madrid bid chief Alejandro Blanco welcomed the "truly impressive" report.
"We have not won anything yet and there is still much to do," he said.