The head of the decommissioning body, Gen John de Chastelain, is to return to Northern Ireland next week in the hope that the IRA and loyalist paramilitaries will disarm speedily.
President George Bush's special envoy on Ireland, Dr Mitchell Reiss, will also join the Taoiseach, Mr Ahern, and the British Prime Minister, Mr Tony Blair, and the Northern parties for the negotiations in Leeds Castle in Kent next week, US sources confirmed.
Gen de Chastelain is due back in Belfast early next week, said a spokesman for the International Independent Commission on Decommissioning. He said the general would be seeking updates from the British and Irish governments on the state of the talks, and would also be monitoring negotiations from Belfast.
The spokesman stressed that he was not in a position to say whether paramilitary disarmament would follow from the talks.
"I am hoping that the IRA and the loyalist paramilitaries will engage in acts of decommissioning." Ahead of talks today between Mr Ahern and Mr Blair in the Prime Minister's constituency of Sedgefield it was also confirmed that Dr Reiss would join the talks at Leeds Castle.
"Dr Reiss's presence is a sign of how serious these talks are being taken. People are cautiously optimistic that a deal can be struck," said a source in the US.
Dr Reiss was likely to act as an observer and monitor of events, willing to offer American assistance were that required, added a second US source yesterday.
"Dr Reiss's decision to travel to Leeds Castle is another sign of the US administration's constructive input to the peace process," said a Government spokeswoman.
The Minister for Foreign Affairs, Mr Cowen, and the Northern Secretary, Mr Paul Murphy, held talks with a number of the Northern parties at Stormont yesterday and also met privately to assess progress in the preparatory talks for Leeds Castle - an assessment that will be in front of Mr Ahern and Mr Blair when they meet in Sedgefield today.
Sinn Féin's chief negotiator Mr Martin McGuinness said that if a deal is not delivered at Leeds Castle, it would then be up to the British and Irish governments to push ahead with elements of the Belfast Agreement that did not require the assent of unionists. In such an eventuality, unionists would be faced with a form of administration that would be more "unpalatable" than what could emerge from Leeds Castle.
The DUP MP Mr Nigel Dodds said that since November his party had been positively engaged in seeking a fair deal for unionists based on effective, efficient, accountable devolution and an end to constructive ambiguity and political fudges.
"The people of Northern Ireland want to see devolution restored, but the terms must be right. There must be completion on the critical issues of decommissioning, paramilitarism and criminality," he said. "As the Prime Minister says, this must be verified. The days of empty words and gestures are over.
"The terms for entry into government for Sinn Féin have been set, and they are unalterable."
The SDLP leader Mr Mark Durkan said if the talks failed his party was offering an alternative where, ahead of the full restoration of devolution, Northern Ireland would be run by a civilian executive answerable to a sitting assembly.
