Barack Obama has been re-elected as president of the United States, narrowly edging Republican challenger Mitt Romney in a hard-fought battle for the White House.
Results from the critical battleground states, especially Florida and Virginia, were still unsettled by mid-evening.
But Obama took Ohio, New Hampshire, Wisconsin and Iowa, four of the seven battlegrounds that were expected to determine the outcome of the election.
Obama has taken to Twitter to thank his supporters, saying "we're all in this together. That's how we campaigned."
Romney was in Massachusetts after a long and gruelling bid for the presidency.