NEW YORK (AFP) - A US judge on Wednesday, Feb 19, 2014, delayed by one week until March 3 the New York terror trial of Osama bin Laden's son-in-law and former Al-Qaeda spokesman Suleiman Abu Ghaith.

The delay is to allow the defence time to collect testimony from the self-declared mastermind of the 9/11 attacks Khalid Sheikh Mohammed, who is held at Guantanamo Bay.

Abu Ghaith's lawyer Stanley Cohen requested a 45-day delay but federal judge Lewis Kaplan sided with government prosecutors who argued that an extra week would be enough.

"This is about as clear as pea coup from the bottom of a cauldron," Judge Kaplan said at one point as Mr Cohen sought to explain the process of collecting evidence from Mohammed.

Mohammed is to receive written questions on Friday and needs at least four days to respond, though it is unclear how long any security clearance would take, Mr Cohen said.

Abu Ghaith's trial had been due to start on Monday.

The 48-year-old Kuwaiti is charged with conspiracy to kill Americans, conspiracy to provide support to terrorists and providing support to terrorists.

He has pleaded not guilty and faces life behind bars if convicted.

He is best-known for making incendiary threats alongside Osama and the now current leader of Al-Qaeda Ayman al-Zawahiri, in the immediate aftermath of 9/11.

US prosecutors allege he was also complicit in the December 2001 shoe bomber plot to bring down an airline flying from Paris to Miami just three months after the 9/11 attacks.

British Al-Qaeda recruit Richard Reid is serving a life sentence in the United States for trying to blow up the passenger jet using bombs hidden in his shoes.

Mohammed is the most high-profile detainee held over the 9/11 attacks and has been held at the US detention facility in Cuba since 2006.