Sinn Féin leader Gerry Adams today said there was "no justification" for the September 11 terror atrocities.
The "fundamentalist approach" of Osama bin Laden was wrong, he said, but added there were people who would consider the chief suspect for the attacks a "freedom fighter".
"Clearly, there are people from his part of the world who support him," he told CNNas he arrived in New York for a six-day visit to North America.
"But I don't think there is any justification for what happened in the twin towers. Or for what happened at the Pentagon, or for what happened to people who died when the plane plunged to the ground in Pennsylvania.
"I don't think there is any justification for that type of fundamentalist approach."
He added: "Of course, one person's freedom fighter, one person's patriot, is another person's terrorist."
Mr Adams said it was "dreadful" that there were wars and conflicts: "But I believe that people have the right to defend themselves and nations have the right to defend themselves." Mr Adams denied the IRA had been pushed into decommissioning following the September 11 attacks and the arrest in August of three suspected IRA members in Colombia on suspicion of training left-wing guerrillas.
"I think those that have tried to present this as the IRA being pressurised are missing the point."
Instead the announcement was to show people there is "another way" of sorting out difficulties by making the peace process work.
Mr Adams is hoping to raise up to £300,000 for families of the victims of the September 11 attacks at the annual friends of Sinn Féin dinner tonight.
The 500 dollars-a-head event is normally used to bring in funds for Sinn Féin, but this year all the proceeds will go to an independent fund for relatives of construction workers killed in the hijack atrocities.
Mr Adams visited the north tower two years ago where friends associated with Friends of Sinn Féin had organised a lunch in the Windows on the World restaurant on the top floor.
He said Ireland was moved by the attacks.
"There was a national day of mourning, of remembrance in Ireland. Maybe it is some very small consolation to those who lost loved ones, to know that the nature of their loss was an encouragement to the peace process back in Ireland."