US president-elect Barack Obama threw his weight behind Chicago's bid for the 2016 Olympics, recording a video message for organizers meeting in Turkey on Friday.
Obama promised his incoming administration "will bring a fresh perspective on America's role and responsibilities around the world" and praised the Olympic movement for its ability to bring the global community together.
Obama said he has "long supported" Chicago's bid and the US "would be honoured" to host the games, in a message to the European Olympic Committee meeting in Istanbul, dpa reported.
Chicago is vying for the 2016 Summer Olympics with Rio de Janeiro, Tokyo and Madrid.
International Olympic Committee President Jacques Rogge meanwhile warned members at the meeting that the games may have to scaled back in light of the ongoing financial crisis that has plunged a number of countries into recession.
Rogge said the financial situation was secure for the 2010 Winter Olympic Games in Vancouver, Canada and 2014 in Sochi, Russia, as well as the 2012 Summer Games in London. But he said members had to ensure the Games do not become too large, too expensive or over-organized.
The number of sports in the Summer Olympics must be capped at 28, he said. There will be 26 sports represented in London.