George W Bush has won another four-year term as United States president after his Democrat challenger John Kerry conceded defeat in one of the bitterest election campaigns in American history.

According to New York Times , Kerry telephoned Bush at the White House to say he had decided not to challenge the results in Ohio.

The race hinges on the mid-eastern state where thousands of uncounted provisional ballots could have become to this election what Florida's butterfly ballots and hanging chads were to the election of 2000.

Kerry's decision not to challenge the Ohio balloting headed off a potential rerun of 2000, when ballot disputes left the election in limbo for more than a month, until the United States Supreme Court declared Bush the nation's 43rd president over Al Gore by halting further recounts in Florida.

Bush won popular vote

However unlike 2000, Bush won the popular vote this time.

With 98 percent of the national vote counted, Bush was leading Kerry by a margin of 51 percent to 48 percent.

Over all, the president had a margin of victory of about 3.5 million votes, and was the first presidential candidate since his father, in 1988, to receive more than 50 percent of the popular vote.

Bush's total of more than 58 million votes is the most ever, besting Ronald Reagan's previous record. Kerry's total of 55 million also beat Reagan's total.

With the contests in Iowa and New Mexico still in question, Bush held a 274 to 252 lead in electoral votes , with 270 needed to win re-election. Iowa and New Mexico were leaning in Bush's direction.

Key state Florida gave Bush solid support this time - he received 3,836,216 votes there, or 52 percent, to 3,459,293, or 47 percent - for Kerry.

The margin of Bush victory in Ohio appeared to be similar. With 99 percent of the vote counted, Bush had bagged 51 percent of the votes against 48.5 percent for Kerry, with the incumbent president leading with 130,000 votes.

Writing on the wall

Ohio allows voters to cast a provisional ballot if election workers find some reason to question their eligibility. Officials said that they knew of 135,149 such ballots. But there could be more. However, not all of these ballots would represent legitimate votes.

Kerry said the writing's on the wall so he won't tie up the country in a legal battle. He would need about 94 percent of the provisional ballots to be valid and all these going to him - an insurmountable task.

In his telephone conversation with the president, Kerry had urged Bush to reunited a divided country.

"We talked about the danger of division in our country and the need, the desperate need, for unity, for finding the common ground, coming together," Kerry told a crowd of supporters at Boston's historic Faneuil Hall . "Today, I hope that we can begin the healing."

Bush: America has spoken

In his victory speech, Bush said: "America has spoken and I'm humbled by the trust and confidence of my fellow citizens."

Bush also adopted a conciliatory tone, saying he would reach out to the 48 percent of voters who backed his opponent.

"I want to speak to every person who voted for my opponent: To make this nation stronger and better, I will need your support and I will work to earn it," Bush told a cheering supporters just blocks away from White House.

The president's clear-cut victory in both the electoral college vote and in the popular vote gives him free rein to promote an aggressive conservative domestic agenda, as well as continue the war in Iraq and the war on terror.

Bush's Republicans also consolidated its hold on the Congress. The party will have at least 231 seats and probably one more for what would be a three-seat pickup in the 435-member House of Representatives.

It has solidified its control on the new Senate by gaining four seats with 55-44 margin, which included a Democratic-leaning independent.