The conviction on terrorism charges of radical North London cleric Abu Hamza justifies the lengthy efforts made to extradite him from the UK, former home secretary David Blunkett said.
A federal court in New York found the preacher guilty of supporting terrorist organisations, including aiding a hostage taking in Yemen and seeking to set up an al-Qaida training camp in the US.
The Egyptian-born cleric, who spread violent messages at the Finsbury Park mosque following the attacks of September 11 2011, was tried under the name Mustafa Kamel Mustafa.
The 56-year-old preacher was jailed in the UK for seven years for soliciting to murder and inciting racial hatred in 2006 and first faced an extradition request from the Americans in 2004.
After a protracted legal battle he was extradited to the US in October 2012.
Mr Blunkett said: "This has been a very long journey to obtain justice, and to ensure that someone who has been so adept at avoiding the just penalty for his extensive activities is at last being brought to book.
"The verdict justifies the extensive measures over many years to ensure through his extradition that he should pay for the misery he brought to others."
Home Secretary Theresa May said: " I am pleased that Abu Hamza has finally faced justice. He used every opportunity, over many years, to frustrate and delay the extradition process.
"His conviction was facilitated by this government's tireless work to successfully remove him from the UK to face trial in October 2012."