Barack Obama has thanked the American people after he was elected to the presidency for a second term.
Though he was re-elected with a reduced margin of victory, he still won comfortably thanks to narrow wins in Ohio, Virginia, Nevada and Colorado.
After walking out with his wife and two daughters in Chicago, Mr Obama said the American people rise or fall together as one nation.
"Tonight more than 200 years after a former colony won the right to determine its own destiny, the task of perfecting our union moves forward," he said.
"Tonight in this election you the American people reminded us of while our road has been hard, while our journey has been hard, we have picked ourselves up, we have fought our way back and we know in our hearts that for the United States of America, the best is yet to come."
Mr Obama vowed to fix an electoral system that saw some voters queuing up for almost nine hours to cast a ballot.
"I want to thank every American who participated in this election," he said.
"Whether you voted for the very first time or waited in line for a very long time — by the way we have to fix that — whether you pounded the pavement or picked up the phone, whether you held an Obama sign or a Romney sign, you made your voice heard, and you made a difference."
President Obama thanked Mitt Romney, Vice President Joe Biden, and his family.
"I wouldn't be the man I am today without the woman who agreed to marry me 20 years ago. Let me say this publicly. Michelle, I have never loved you more," he said.
"Sasha and Malia. Before our very eyes you are growing up to be two strong, smart, beautiful women just like your mom."
With Florida and Alaska still to be called, President Obama won 303 electoral votes, more than the 270 required to claim victory.
Victory was declared about 4pm AEDT after ekeing out narrow wins in Ohio, Colorado, Virginia and Nevada.
"This happened because of you. Thank you," Barack Obama tweeted after the election was called.
He then tweeted a photo of himself hugging his wife along with the words "Four more years."
Within a matter of minutes it became the most popular tweet of all time, being retweeted more than 300,000 times.
Despite a struggling economy Mr Obama prevailed thanks in part to the popularity of his auto bailout in the industrial states of Ohio and Michigan.
His popularity among Hispanic voters almost made the difference in the states of New Mexico, Colorado and Nevada.
Romney won all of the states taken by John McCain in 2008, as well as North Carolina and Indiana.
In Vigo County, Indiana, which has sided with the winner in every presidential election since 1956, Obama has won by 160 votes out of more than 36,000 cast.
Officials are reporting high turnout around the country, where voting is non-compulsory.
Author: Nick Pearson. Approving editor: Henri Paget