Update 12 noon: Former CIA Director John Brennan has said no country should feel immune from a terrorist attack or having terrorists use their country for "whatever purposes".
He said he knew the Irish leadership was aware of the need to "stay vigilant" and that British police have close relationships with the gardaí, frequently sharing information.
Mr Brennan told Today with Sean O'Rourke that we should not be fearful to the point of limiting freedom and liberties that were hard fought for in the West.
He praised counter terrorism officials across the world who, he said, have stopped a lot of attacks.
Mr Brennan said that the only way to look at those who have carried out recent attacks is as psychopaths and murderers, who have distorted the teaching of Islam.
He said he was pleased to see Imans refuse to say prayers at the burials of the perpetrators.
Mr Brennan said ISIS is quite different to al-Qaida, which he described as a structured organisation who took months and years to put together attacks.
ISIS, he said, was taking advantage of the cybersphere to encourage people to carry out attacks in their name.
Mr Brennan, who was in the White House situation room during the Navy Seal Osama Bin Laden operation, said the operation was the culmination of many years of intelligence and there was "a lot of hand-wringing" in the months preceding it.
He described it as a nerve wracking time with the lives of Americans on the line and "minutes that seemed like hours".
The Tánaiste has said there is no complacency when it comes to a possible terrorist attack on Irish soil.
Senior gardaí said yesterday that they could respond to a terrorist attack in Dublin within minutes, but were still establishing response times in rural areas.
Justice Minister Frances Fitzgerald said that while an attack here is unlikely, the Gardaí is working hard at ensuring safety across Ireland.
"It's possible but unlikely," she said. "There's no complacency. We continue to gather information and work with colleagues internationally (and) make sure we exchange data.
"There's a strict regime in place, but it's challenging with the amount of international travel people do these days. We don’t want our democracies to be closed down by these people."
Meanwhile, a prominent Muslim figure had called for a dedicated and ‘friendlier’ garda system for reporting concerns or suspicions regarding radicalisation.
Faheem Bukhatwa, a senior leader in the Libyan community, said gardaí and the Muslim community, in general, need to take “preventative action”.
Speaking to the Irish Examiner, he said he believes that a phone contact system, not one run by anti-terrorism officers but staffed by community gardaí and professionals like psychologists, should be set up.
“I am pretty concerned for the Irish community as a whole,” said Mr Bukhatwa.
“We do not want anything to happen. The Muslim community do not want anything wrong to happen to anybody, not only for those people who might be affected but the Muslim community who will suffer if anything happens.”
The college lecturer said measures should be brought in now to try and stop anything from happening.
“Preventative action needs to be taken. Gardaí will need to do that and the Muslim community, in general, needs to take part in that.
“We need to fight this menace which is taking young people and turning them into monsters.”