Barack Obama wins US election

US President Barack Obama celebrates on stage as confetti falls after his victory speech.

US President Barack Obama waves with his daughters Malia and Sasha, and wife Michelle, before addressing supporters

Supporters wave flags and listen to President Barack Obama's victory speech in Chicago.

US President Barack Obama and first lady Michelle Obama celebrate with Vice President Joe Biden and his wife Jill after his election night victory speech in Chicago.

US Republican presidential nominee Mitt Romney waves with his wife Ann alongside Republican vice presidential nominee Paul Ryan, right, and his wife Janna after Romney delivered his concession speech.

People celebrate in New York's Times Square after President Barack Obama was projected to win the US presidential election.

Barack Obama tweeted this picture of himself and wife Michelle moments after winning re-election.

Supporters of US President Barack Obama cheer during his election night victory rally in Chicago.

Ajay Narayan cheers as the race is called for US President Barack Obama at the Nevada State Democrats' election night party in Las Vegas.

Supporters of US President Barack Obama cheer the news of the president's re-election.

Supporters of U.S. President Barack Obama cheer during his election night victory.

Supporters of US President Barack Obama cheer during his election night rally in Chicago.

Supporters of US President Barack Obama cheer during his election night rally in Chicago.

A Romney supporter rubs his head as voting returns are announced at the election night rally for Mitt Romney.

Supporters of US President Barack Obama cheer during his election night rally in Chicago.