Ulster Unionist Party leader Mr David Trimble has accused the IRA leadership of living in an "unreal world".
With Sinn Féin leader Mr Gerry Adams due to have talks with the British Prime Minister later this afternoon, Mr Trimble said: "It was their recklessness that precipitated all of this, and it is up to them to sort it out".
Mr Trimble was reacting to the Provisionals' accusation that the UUP was seeking to impose unacceptable and unrealistic ultimatums.
Arriving at 10 Downing Street for talks with Mr Blair, SDLP leader Mr Mark Durkan dismissed the IRA statement. "I don't think there is anything to get worked up about either one way or the other about the IRA's statement," he said.
"There really isn't anything there for unionists to fume about and there isn't anything else for any of the rest of us to fume about either. We have heard exactly that type of shrill statement from the IRA before, not least in these kinds of circumstances".
PA