New York mayor Michael Bloomberg and Senator Hillary Clinton told International Olympic Committee (IOC) members about the city's enthusiasm for the Games, backed by video clips from President George W. Bush and former president Bill Clinton.
The IOC votes later on Wednesday on which of the five candidates -- London, Madrid, Moscow, New York or Paris -- will be awarded the Games. The announcement is due at around 1715 IST.
The Americans opened their hour-long presentation with a film in which ordinary New Yorkers of many different ethnic origins spoke in almost as many different languages of their enthusiasm for the city and the Olympics.
The Frank Sinatra song of the city that never sleeps played and the voice-over spoke of "the city where anything can happen and, on a daily basis, does".
Former Olympic champions, swimmer Janet Evans and long jumper Bob Beamon, described the fun athletes would have in the centrally located Olympic village and the vibrant entertainment available to them in Manhattan.
Muhammad Ali, possibly the greatest sports personality of them all, was introduced to prolonged applause.
"NewYorkers asked ourselves 'can we recover', 'will we rebuild'?" he said.
"Withouthesitation, New Yorkers stood up and said yes. This spirit will be given to your Games.
"New Yorkers never give up --not now, not ever."
Former First Lady Clinton said: "Let me say loud and clear -- we are 100 percent committed to making the 2012Games a truly spectacular event."
Filmprominently featured the Manhattan skyline and the Statue of Liberty to emphasise her point.