The Taoiseach said yesterday he supported the attacks on Afghanistan.
Mr Ahern said he hoped, like everyone else, the targets would remain focused and restricted as far as was possible.
"But this is a legitimate action by the US in self-defence under the UN Charter. And I support their efforts."
Mr Ahern said he held the same view as everybody else in the European Union. "It is in conformity, it is a legitimate right for the US to take action under the UN Charter. They have done that."
Asked if Irish airspace had been used in the attacks, Mr Ahern replied: "No. I do not think we have been called on to do anything at this stage."
Mr Ahern said he believed the US had worked hard "to get a coalition across the world".
Nobody liked to see any civilian getting killed or injured, he said, but people understood it was a war situation. "So I think we will be using the UN Security Council meeting (held last night) to make sure that both issues are dealt with side by side and not one to the exclusion of the other."
He said if the Government came across anything it was particularly concerned about, it would be their obligation to highlight that. "But at this stage I think this is an international effort, practically the entire world are out to take action to see this resolved."
Mr Ahern said he hoped the Taliban regime would be toppled.
The bombing was condemned by the Green Party, which said it would not succeed in dealing with the problem and would be counter-productive.
The party's foreign affairs spokesman, Mr John Gormley, said the attack would lead to a spiral of violence that could catapult us into a third world war.
The Labour Party leader, Mr Ruair∅ Quinn, welcomed the decision of the Government to seek an early meeting of the Security Council to discuss the situation.
While the military action was not unexpected, he said, there must be concern that air strikes and missile strikes of this nature will lead to the loss of additional innocent lives.