Now it's straight to work: Obama halts Guantanamo trials

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His rhetoric over the past four days has also made clear he intends to push Congress hard for hundreds of billions of dollars to stimulate the economy.

The need for action was underlined by steep falls in US share prices after he made his inaugural speech.

In a sweeping passage in his speech, he said: "The state of the economy calls for action, bold and swift, and we will act - not only to create new jobs, but to lay a new foundation for growth. We will build the roads and bridges, the electric grids and digital lines that feed our commerce and bind us together."

President Obama's new team is keen to be seen to be tackling the crises and the announcement about Guantanamo Bay was issued just hours after the inauguration while the President and First Lady were attending a stream of balls in their honour.

White House chief of staff Rahm Emanuel, one of the new behind-the-scenes powers in Washington, signed the memorandum suspending the war crimes trials for 120 days "in the interests of justice".

The US military currently has charges pending against 21 men at Guantanamo and officials have said they intend to charge dozens more.

Pre-trial hearings in two cases - the trial of five men charged in the 9/11 attacks and Omar Khadr, a Canadian accused of killing a US soldier in Afghanistan - were due to take place this week.

However, closing Guantanamo Bay altogether poses a series of problems, including what to do with several hundred inmates. The administration is likely to increase pressure on allies, including Britain, to give new homes to suspected terrorists held at the detention centre who cannot be returned to their native homelands because they would be executed.

Gordon Brown has signalled he is willing to accept some, although other countries, including Australia, are not keen.

Mr Obama is also expected to form a team to move forward the stalled Middle East peace process. As the first black president, Mr Obama has already made history but has to deal with overwhelming expectations that he has a magic cure for America's ills.

The US Senate, which traditionally moves swiftly to affirm a new president's cabinet, approved six members on Tuesday.

However, Hillary Clinton's approval as Secretary of State was postponed after a fresh row over foreign donations to a foundation headed by Bill Clinton.