A new photo of Khalid Sheikh Mohammed recently surfaced
Alleged 9/11 mastermind Khalid Sheikh Mohammed is to be sent from Guantanamo Bay to New York for trial in a civilian court, the US has confirmed.
Attorney General Eric Holder said he would be transferred from the US prison camp in Cuba with four other suspects.
Mr Mohammed has admitted planning the 9/11 attacks, the US military says.
The move is part of US President Barack Obama's effort to close Guantanamo, but some relatives of 9/11 victims say they oppose a federal court trial.
Responsibility for the case will go to the Southern District of New York, with proceedings taking place near Ground Zero.
The five men have until now been facing prosecution at US military commissions in Guantanamo. The government had faced a 16 November deadline to decide how to proceed in their cases.
Speaking in Tokyo ahead of Mr Holder's announcement, Mr Obama said Khalid Sheikh Mohammed would face "most exacting demands of justice".
Khalid Sheikh Mohammed has been described by US investigators as "one of history's most infamous terrorists".
They say he has admitted being responsible "from A to Z" for the 9/11 attacks.
Paul Reynolds, BBC World Affairs correspondent
The decision is a major step towards Mr Obama's target of closing Guantanamo Bay a year after he took office. However, it will not solve all the remaining problems.
The most difficult is what to do with an estimated 70 prisoners against whom there is not enough useable evidence for either a military or a civilian trial yet whose release is regarded as too dangerous. Other prisoners might also face civilian trial or military commissions, so Mr Obama appears unlikely to decide that a civilian court should be the only place where suspects will face justice.
It remains to be seen whether the federal court will accept any alleged confession by Khalid Sheikh Mohammed as it might have been based on water-boarding, or whether, in a courtroom very close to Ground Zero, he will seek to glory in the attacks.
Believed to be the number three al-Qaeda leader, he was captured in Pakistan in March 2003.
He told a pre-trial hearing at Guantanamo in December 2008 that he wanted to plead guilty to all charges against him.
But intelligence memos released earlier this year revealed he had been subjected to harsh interrogation techniques including water-boarding on multiple occasions since his capture - potentially rendering some evidence inadmissible.
The other four men - the two Yemenis, a Saudi and a Pakistani-born Kuwaiti who have shared hearings with him at Guantanamo Bay - are also accused of helping plan and finance the attacks.
The decision to try them in a New York court appears to be part of Mr Obama's efforts to close Guantanamo by 22 January 2010.
His administration says it will try some detainees in US courts and repatriate or resettle others who are not perceived as a threat.
However, questions remain over the fate of those assessed as dangerous but who for legal reasons could not be prosecuted in a US court - prompting suggestions that the deadline will slip.
And, says the BBC's Jonathan Beale, some families of those who died in the 9/11 attacks have already voiced strong opposition to any attempt to try their alleged architect in New York.