Barack Obama has won a second term as US President after defeating his republican opponent Mitt Romney in last night's American election.
Obama passed the required 270 votes in the electoral college to secure his re-election, and prompt Romney to concede defeat.
The jubilant Obama campaign tweeted "Four more years" along with a picture of himself hugging wife Michelle, who will be First Lady once again.
The Twitter account said, "We're all in this together. That's how we campaigned, and that's how we are. Thank you - bo [Barack Obama].
"This happened because of you. Thank you."
Celebrations have already begun in Chicago where the President is likely to address a victory rally in the next few hours.
Obama's exact margin of victory is not yet certain as counting is still to be completed in some states.
The 44th US President won despite a strong challenge from his Republican challenger and widespread dissatisfaction with the economy.
The nine swing states, including the crucial Ohio, proved vital in Obama's re-election, as predicted.
There were not many surprises in the traditional Democratic or Republican heartlands, as both Obama and Romney won their respective solid states.
Romney did secure North Carolina and Indiana, states won by Obama in 2008.
The mood in the Romney campaign started to deteriorate as the millionaire Mormon's hopes of entering the White House began to fade.
Opinion polls ahead of the elections predicted a close race, however Obama continued to enjoy a marginal lead throughout.