Withdrawing access to Shannon Airport and Irish airspace from the US would be "a hostile act", the Taoiseach, Mr Ahern, said last night.
Defending his Government's view on RTÉ news yesterday, Mr Ahern said he was not prepared to withdraw access which had existed "for over forty years".
"For us to withdraw what has been there for over 40 years would be seen as a hostile act," he said.
"We have a relationship with the United States; I think we've had that understanding for a long way back. For us to withdraw something that's been there since 1955 was not something I was prepared to do."
Responding to reports of widespread opposition at home to the use of Shannon by US troops in a military campaign, Mr Ahern insisted this did not constitute active involvement by Ireland.
"That is not engaging in war. There is long precedent; there is clearly-stated constitutional and legal arguments; and in compliance with our neutrality, allowing a civilian airport for peripheral ancillary facilities for landing is not engaging or supporting the war effort," he said.
"We're not going to be doing anything of assistance. Overflights and landing at Shannon, while they're not many now, are very limited because three of the main carriers have pulled out."
Mr Ahern denied Mr Bush had applied pressure on the Shannon issue in Washington recently.
"President Bush's only conversation with me about these matters was to thank Ireland and our effort in the formulation of 1441," he said.
"We wanted a second resolution so there would be legal clarity; it would have been a better situation. It wasn't achieved. For us, because there is no second resolution, our participation is not there," said Mr Ahern.