Barack Obama has won the 2012 US Presidential elections and is going to remain in the White House for another four years.

"Four more years," Obama tweeted. "We're all in this together. That's how we campaigned, and that's who we are. Thank you.This happened because of you."

Democrat America cheered and celebrated the victory at the end of a very tight and strenuous campaign.

Democrats have also retained control of the Senate in the crucial congressional elections.

People flocked to the streets across the US and a crowd of jubilant Obama supporters gathered in front of the White House, echoing Obama's tweet by chanting "Four more years! Four more years!"

Obama will hold his post-election speech at McCormick Place in Chicago, Illinois.

Romney is also expected to make a speech at the Boston convention centre, but the atmosphere there is completely different, as it is now almost certain that the former governor of Massachusetts, who has not conceded defeat, has lost the race for the White House.

Supporters of US President Obama cheer during his election night rally in ChicagoReuters
Supporters of US President Obama cheer during his election night victory rally in ChicagoReuters
Supporters react while watching results during Romney's election night rally in BostonReuters
Rev. Jesse Jackson reacts after it was announced the state of Ohio was called for US President Barack Obama during an election night rally in Columbus, OhioReuters
President Barack Obama supporters cheer while watching the returns prior to his election night rally in ChicagoReuters
Two Republican women watch results come in for the US presidential election in Salt Lake CityReuters
Supporters of US President Obama cheer during his election night rally in ChicagoReuters
Ajay Narayan cheers as the race is called for US President Barack Obama by a television network during the Nevada State Democrats' election night party at the Mandalay Bay Resort in Las VegasReuters
President Barack Obama supporters cheer while watching the returns prior to his election night rally in ChicagoReuters
Supporters embrace while watching results during Romney's election night rally in BostonReuters
Supporters of US President Obama cheer during his election night rally in ChicagoReuters
The stage and podium await US Republican presidential nominee Mitt Romney to address his supporters at his election night rally in BostonReuters