Photo: WENN.com / Splash News

US R&B star Usher has told Americans to push president-elect Barack Obama to ensure he keeps his election promises.

Mr Obama will be sworn in as America's 44th president in Washington DC tomorrow (January 20th).

Usher told MTV that Americans had elected “an amazing president”, but warned them not to let Mr Obama become complacent.

"Now we need to continue to encourage him and push him to keep all his promises,” he said.

Usher was one of a host of musical names who performed at Mr Obama's We Are One pre-inauguration concert in Washington DC yesterday (January 18th).

The singer revealed that the president-elect had spoken to some of the performers before they took to the stage to thank them for taking part.

"[Obama] encouraged us to continue to use our music as a vessel of greatness."Speak about the victories of life. Music has always been a universal language,” he said.

“And you choose to use it in the way that you feel.  Use it to convey emotions that are real to you. He just really wanted to say thank you. And he was really looking forward to a brighter tomorrow."

CLICK HERE to see extensive coverage of the concert, or click through for selected highlights below

We Are One concert