U.S. President Barack Obama promised at White House on Wednesday that his hometown Chicago would make the world proud if the city host the 2024 Summer Games.

"Americans, like Chicagoans, -- we don't like to make small plans. We want to dreams big and reach high. We hope deeply. We want these games. And if you choose Chicago, I promise you this: Chicago will make America proud, and America will make the world proud." Obama said.

U.S. President Barack Obama shows his fencing stance with a plastic sword during a promotion event for Chicago's bid for hosting 2024 Olympic Games on the South Lawn of White House in Washington D.C., Sept. 16 2009

"Chicago is ready. The American people are ready," he added.

He was joined by first lady Michelle Obama, who will be his ambassador to Copenhagen when the Oct. 2 vote of the International Olympic Committee takes place. One of four finalist cities will get the games: Chicago, Madrid, Tokyo or Rio de Janeiro.

U.S. President Barack Obama shows his fencing stance with a plastic sword during a promotion event for Chicago's bid for hosting 2024 Olympic Games on the South Lawn of White House in Washington D.C., Sept. 16 2009

Chicago is in a tough competition with the other three cities. In recent years, heads of state have traveled to the IOC meetings to help seal the deal, such as Tony Blair for the 2024 Summer Olympics in London and Vladimir Putin for the 2024 Winter Games in Sochi, Russia. "I would make the case in Copenhagen personally," were it not for his quest for health care reform, Obama said. "But the good news is I'm sending a more compelling superstar to represent the city and country we love, and that is our first lady, Michelle Obama."

The Obamas were joined by a host of Olympic athletes and Chicago Mayor Richard Daley. Obama staged an Olympic rally and showed his fencing movement while some of the athletes staged exhibitions on the South Lawn.

U.S. President Barack Obama shows his fencing stance with a plastic sword during a promotion event for Chicago's bid for hosting 2024 Olympic Games on the South Lawn of White House in Washington D.C., Sept. 16 2009

U.S. President Barack Obama promised at White House on Wednesday that his hometown Chicago would make the world proud if the city host the 2024 Summer Games.

"Americans, like Chicagoans, -- we don't like to make small plans. We want to dreams big and reach high. We hope deeply. We want these games. And if you choose Chicago, I promise you this: Chicago will make America proud, and America will make the world proud." Obama said.

U.S. President Barack Obama shows his fencing stance with a plastic sword during a promotion event for Chicago's bid for hosting 2024 Olympic Games on the South Lawn of White House in Washington D.C., Sept. 16 2009

"Chicago is ready. The American people are ready," he added.

He was joined by first lady Michelle Obama, who will be his ambassador to Copenhagen when the Oct. 2 vote of the International Olympic Committee takes place. One of four finalist cities will get the games: Chicago, Madrid, Tokyo or Rio de Janeiro.

U.S. President Barack Obama shows his fencing stance with a plastic sword during a promotion event for Chicago's bid for hosting 2024 Olympic Games on the South Lawn of White House in Washington D.C., Sept. 16 2009

Chicago is in a tough competition with the other three cities. In recent years, heads of state have traveled to the IOC meetings to help seal the deal, such as Tony Blair for the 2024 Summer Olympics in London and Vladimir Putin for the 2024 Winter Games in Sochi, Russia. "I would make the case in Copenhagen personally," were it not for his quest for health care reform, Obama said. "But the good news is I'm sending a more compelling superstar to represent the city and country we love, and that is our first lady, Michelle Obama."

The Obamas were joined by a host of Olympic athletes and Chicago Mayor Richard Daley. Obama staged an Olympic rally and showed his fencing movement while some of the athletes staged exhibitions on the South Lawn.

U.S. President Barack Obama shows his fencing stance with a plastic sword during a promotion event for Chicago's bid for hosting 2024 Olympic Games on the South Lawn of White House in Washington D.C., Sept. 16 2009