US President-elect Barack Obama and Vice President-elect Joe Biden joined a large jubilant crowd in an open-air welcome concert in Washington on Sunday afternoon, kicking off the inauguration celebrations in the national capital.

"The dream of our founders will live on in our time ... What gives me hope is what I see when I look out across this mall," Obama told thousands of people gathering on the National Mall grounds in front of the Lincoln Memorial.

President-elect Barack Obama and his wife Michelle arrive for the We Are One: Opening Inaugural Celebration at the Lincoln Memorial in Washington, January 18, 2009. [Xinhua/Reuters]

He noted that "there is no obstacle that can stand in the way of millions of voices calling for change."

The president-elect said it is the American people who give him hope that the country's problems can be overcome, and that the change he has promised can be fulfilled.

In some brief remarks, Biden said that the "marble domes" and towers of Washington surrounding the crowd represent "the majesty of a great nation -- all built stone by stone by American men and women."