Democrat candidate Barack Obama has been elected as the United States first black president following his historic win over his Republican rival John McCain.

american presidential election barack obama 051108 05 The 47-year-old father of two, who will be inaugurated as the 44th US president on Jan 20, 2009, has however inherited an economy mired in the worst financial crisis since the 1930s, two wars in Afghanistan and Iraq and a nuclear showdown with Iran.

Television networks projected his victory over McCain after Obama solidified traditional Democratic states and cut deep into the Republican territory which his rival needed to control to win the White House.

Obama garnered 338 against McCain's 163 of the 538 electoral college votes. He won 62 million voters (52 percent), while McCain has 55 million voters (47 percent).

Obama's historic inauguration will complete a stunning ascent to the pinnacle of US and global politics from national obscurity just four years ago and close an eight-year era of turbulence under President George W Bush.

At 12.20pm local time, McCain conceded defeat and congratulated Obama on his victory.

Obama has earlier captured key states Ohio, Pennsylvania and Florida to leave McCain a near-impossible route to the presidency.

On a dramatic night after millions of people cast votes in an election that could reshape US politics, Obama appeared a virtual lock to make history by capturing the White House and giving Democrats a monopoly on power in Washington.

barack obama and joe biden No one since John F Kennedy in 1960 has lost two of the critical triumvirate of Ohio, Pennsylvania and Florida and gone on to win the presidency.

Obama also captured New Mexico, another Republican seat McCain needed to hold to keep his slim White House dreams alive.

Obama scored an easy victory in Washington state, Oregon and delegate rich California.

american presidential election barack obama 051108 02 Obama also won Massachusetts, Connecticut, Illinois, New Jersey, Maine, New Hampshire, Washington DC, Delaware, Michigan, Wisconsin, Rhode Island and Minnesota.

McCain captured Kentucky, Tennessee, West Virginia, South Carolina and Oklahoma, Alabama, Arkansas, Wyoming, Louisiana, Kansas and Texas.

Other normally Republican states, North Carolina and midwestern Indiana were too close-to-call, but Obama has won over Virginia.

As expected, McCain snapped up Kentucky and West Virginia and Obama won Vermont.

Democrats control Senate and House

Democrats took a third seat from Republicans in the Senate on Tuesday, putting them on track to win a majority with 56 seats in the 100-member legislative body.

Virginia's Mark Warner filled a seat being vacated by veteran Republican Senator John Warner, who is of no relation to the winner, while Democrat Jeanne Shaheen unseated Republican John Sununu in New Hampshire.

american presidential election john mccain 051108 03 But Republican senate majority leader Mitch McConnell clung on, meaning that Democrats cannot now win the 60 seats they need in the 100-seat chamber needed to frustrate Republican obstruction tactics.

Among the Republican casualties was Elizabeth Dole in North Carolina, wife of former Senate majority leader and defeated 1996 presidential nominee Bob Dole.

CNN reported that exit polls showed that the economy was the top priority, being named by 62 per cent of voters, compared to Iraq with 10 per cent, terrorism on nine per cent and healtcare on nine per cent.

Obama made a short election day trip to the midwestern swing state of Indiana, after casting his vote alongside wife Michelle with daughters Sasha and Malia close by.

"I feel great and it was fun, I had a chance to vote with my daughters," he said.

"I noticed that Michelle took a long time though. I had to check to see who she was voting for," the Hawaiian-born US senator from Illinois said with a laugh.

McCain kept silent as he voted in his home state of Arizona, but later led a boisterous rally in Grand Junction, Colorado, promising supporters: "We're going to win it."

McCain, a former Vietnam war prisoner would be at 72 the oldest presidentinaugurated for a first term if elected.

Obama, the son of a black Kenyan father and white mother from Kansas, would become the first African-American president after a stunning rise to the pinnacle of US politics.

Full election results

- AFP