Mr Donaldson warned there could be a 'serious split' in the Ulster Unionist party following the statements on Tuesday by David Trimble and Sinn Fein president Gerry Adams.

The Lagan Valley MP described what was on offer from the IRA as falling well short of unionist demands.

"They are merely agreeing to appoint a substitute for Martin McGuinness who is already appointed as a liaison to the International Body on Decommissioning," he said.

He said the statement by Sinn Fein repeated previously made declarations and he could not take the party at its word.

Jeffrey Donaldson: Certainty needed on arms issue

"Gerry Adams said a year ago that the conflict was over, done with and gone - since Gerry Adams uttered those words, the IRA have committed five murders and have engaged in illegal smuggling of guns from America.

"On the basis of past evidence, words are not enough, the IRA say one thing and do another."

Resignation threat

Fellow anti-Agreement Ulster Unionist William Thompson threatened to leave the party if it abandoned the policy of "no guns, no government."

Speaking during a BBC Radio Ulster interview, the dissident MP said the policy was too important to Northern Ireland and to democracy.

The statements by Sinn Fein and the Ulster Unionist Party (UUP) have received a broad welcome from those in favour of the Good Friday Agreement.

BBC NI's Political Editor Stephen Grimason: Two sides trying to reach out to each other

But the anti-agreement Democratic Unionist Party (DUP) said Sinn Fein's acknowledgement that decommissioning was "an essential part of the peace process" did not go far enough.

DUP Assembly member Nigel Dodds said that Sinn Fein had refused to "commit to actual decommissioning" and their statement contained nothing new.

UUP leader David Trimble earlier expressed "deep regret" at the suffering past divisions had caused to both Northern Ireland traditions. These words were echoed by Sinn Fein President Gerry Adams.

The Social Democratic and Labour Party (SDLP) also issued a statement stressing their unequivocal commitment to the "comprehensive and successful implementation of the Good Friday Agreement".

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SDLP leader John Hume said there was no more time to waste.

"At this critical juncture we urge all parties to continue working in the new spirit of understanding that has come to characterise the latter stages of the review and so ensure its successful completion," he said.

Northern Ireland Secretary Peter Mandelson appealed for people to be patient and said he was confident that weapons would be given up.

He said: "I expect to see not only decommissioning achieved, I expect to see all parts of the Good Friday Agreement implemented fully in the coming year."

David Andrews: Praises visionary statements

There was warm praise for the UUP and Sinn Fein statements from Irish Foreign Minister David Andrews, who described them as "generous and visionary".

"I congratulate all of the parties for the courage and leadership they are showing," he said.

Other pro-agreement parties, including those linked to loyalist paramilitaries, have also been throwing their support behind efforts to make progress towards devolution.

David Adams from the Ulster Democratic Party, which is linked to the paramilitary Ulster Defence Association said they welcomed the recent political developments that had taken place within the review process.

Positive and constructive

"We regard these developments as positive and constructive and providing of a real opportunity for the full implementation of all aspects of the Good Friday Agreement," he said.

The Progressive Unionist Party, which is linked to the paramilitary Ulster Volunteer Force, said it had always been their view that political institutions should be set up regardless of the decommissioning issue.

A statement said: "We believe the process of decommissioning should be the sole remit of the Independent Commission on Decommissioning, and as such should be completely removed from the political equation."

The Workers Party said they welcomed the statements by David Trimble and Gerry Adams.