Barack Obama hunkered down at home in Chicago today and turned to the task of building the administration that will extricate the United States from the war in Iraq and deliver the change he promised to voters.

After a landslide election victory that saw him chosen as America's first black president, the Democrat is expected to spend the next few days picking the men and women he wants around him when he moves into the White House.

Mr Obama himself knows that he has no time to waste – as he told more than 100,000 supporters packed into Chicago's Grant Park for his victory rally last night: "We know the challenges that tomorrow will bring are the greatest of our lifetime: two wars, a planet in peril, the worst financial crisis in a century."

The first name written down on Mr Obama's team sheet appears to be that of Rahm Emanuel, the combative but highly effective Chicago congressman who served in Bill Clinton's White House in the 1990s. Sources close to the President-elect said that Mr Emanuel had agreed to return as White House chief of staff.

Other posts likely to be filled within days include Treasury Secretary, Secretary of State and Defence Secretary – even though Mr Obama will not be sworn in as the 44th President of the United States until January.

“The need for a seamless transition is greater than it has been in our adult political lifetime,” said William Galston, a former domestic policy adviser to President Clinton who is now a professor at the University of Maryland. “With two wars abroad and an international financial crisis going on, there cannot be a period in which the new administration is just getting up to speed."

Mr Obama's victory is the culmination of an extraordinary personal tale – that the son of a Kenyan goatherd can be elected to the highest office in the land still defies belief.

But as Obama fans around the world celebrated his success on the beaches of Brazil and the boulevards of Berlin – and their leaders lined up to offer their congratulations - he was already being dragged into problems more than two months before taking office.

Among those foreign leaders offering their congratulations was Hamid Karzai, the US-backed President of Afghanistan, who noted claims that dozens of women and children had been killed in a US airstrike on Monday that hit a wedding party in the province of Kandahar.

"We cannot win the fight against terrorism with airstrikes,” Mr Karzai said. “This is my first demand of the new President of the United States - to put an end to civilian casualties.”

There was also sabre-rattling by the Russian President, Dmitry Medvedev who used his first annual address to parliament to launch a stinging attack on US policy and announce the Kremlin was to station new missiles near the Polish border in response to US plans for an anti-missile system.

“I would like to stress: we have no problems with the American people. We have no innate anti-Americanism,” Mr Medvedev said. “We hope that our partners -- the new US administration -- will make a choice in favour of fully-fledged relations with Russia."

Other world leaders welcomed Mr Obama's victory – “Your election has raised enormous hope in France, in Europe and beyond,” said President Sarkozy of France.

But the election result led to typically partisan squabbles on the floor of the Commons as David Cameron, Leader of the Opposition, clashed with Gordon Brown on the need for Obama-style change in the UK after Mr Brown told MPs that Mr Obama would be a "true friend to Britain".

“On the day the American people voted for change aren’t people in this country entitled to ask: how much longer have we got to put up with more of the same from a Government that has failed?” Mr Cameron demanded.

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