Image copyright Reuters Image caption Sulaiman Abu Ghaith was brought to New York from Turkey last year to face trial

A man US prosecutors say was al-Qaeda's spokesman after 9/11 has testified Osama Bin Laden wanted him "to deliver a message to the world".

Sulaiman Abu Ghaith, 48, took the stand in his own defence at his terrorism trial in New York City on Wednesday.

He has pleaded not guilty to charges he conspired to kill Americans, and his defence lawyers say he had no advance knowledge of the attacks.

The case is one of the highest-profile terror trials in a US civilian court.

On Wednesday, Mr Abu Ghaith told the court he arrived in Afghanistan in June 2001 because he had a "serious desire to get to know the new Islamic government" there.

At the time, Afghanistan was nominally controlled by the Taliban Islamist militia.

Speaking through an interpreter, Mr Abu Ghaith testified that on the night of 11 September 2001, Bin Laden despatched an aide to drive him into a mountainous area of Afghanistan for a meeting.

"I wanted to see what he had, what is it he wanted," Mr Abu Ghaith testified of the man who would later become his father-in-law.

When they met Bin Laden said, "Did you learn what happened? We are the ones who did it," Mr Abu Ghaith testified.

'Murderous power'

Bin Laden then asked what Mr Abu Ghaith thought would happen next.

Mr Abu Ghaith testified that he responded with a prediction America "will not settle until it kills you and topples the state of Taliban".

"I want to deliver a message to the world," Bin Laden then told him, Mr Abu Ghaith testified. "I want you to deliver the message."

Prosecutors have argued Mr Abu Ghaith used the "murderous power of his words" to rally militants against America after the 11 September 2001 attacks.

Assistant US Attorney Nicholas Lewin has previously said Mr Abu Ghaith spent time at the al-Qaeda camps inspiring the recruits to kill.

Prosecutors also allege that he agreed to appear in the group's propaganda videos after 11 September 2001 to call for further violence "while our buildings still burned".

The Kuwaiti preacher testified on Wednesday that those videos were based on "quotes and points by Sheikh Osama" and were intended to be religious sermons, encouraging Muslims to fight oppression.

Mr Abu Ghaith also denied allegations he had prior knowledge of the failed shoe-bomb airline attack by Richard Reid in December 2001.

Image copyright AFP Image caption Suleiman Abu Ghaith appeared in several al-Qaeda videos, including one released the day after the 9/11 attacks, prosecutors say

Mr Abu Ghaith's remarks came a day after a judge ruled jurors would not hear testimony from Khalid Sheikh Mohammed, the self-described mastermind of the 9/11 attacks.

Mr Mohammed had previously written in a statement that Mr Abu Ghaith had no military role in al-Qaeda.

Mr Abu Ghaith was arrested last year in Turkey and brought to New York to face trial. He faces up to life in prison if convicted of the charges against him.