In the US, Mr Martin McGuinness of Sinn Fein has criticised Gen de Chastelain's commission on disarmament for not "exerting its authority". He said the UUP leader, Mr David Trimble, had been allowed to dictate to it.
Mr McGuinness also said the way the British government and the UUP had dealt with decommissioning had "set back the prospect of all the parties achieving that by many years".
In a hard-hitting press conference before meeting officials at the White House, Mr McGuinness repeatedly criticised Mr Trimble and the Northern Secretary, Mr Peter Mandelson, who he referred to as "Peter Mandlespin".
At one stage Mr McGuinness unfolded a Sinn Fein map showing "the British military garrison in Ireland", comprising army bases, RUC barracks and "spy posts", to reinforce his call for "all guns to be taken out of commission, not just IRA arms".
Some of the effects of Mr McGuinness's visit to New York and Washington this week may possibly be seen in yesterday's editorial in the New York Times, where he had earlier met the editorial board. The editorial criticises the IRA's refusal to disarm but also calls "Mr Trimble's threats and deadlines counterproductive" and urges him to withdraw his threat to resign. "He should recognise that threats undermine the process of reconciliation and confidence-building on which future progress in Northern Ireland depends," the editorial said.
Mr McGuinness said at his press conference that the de Chastelain commission "has been undermined from the very beginning by the British government and the unionists and has not been allowed to do its job".
"David Trimble effectively self-appointed himself as head of the decommissioning body and while this situation was allowed to continue, in my view, there was never any prospect of all the parties collectively succeeding in achieving decommissioning within the time-frame of the agreement. "In fact, I believe the British/unionist approach has set back the prospect of all the parties achieving this by many years."
Asked to clarify if this meant the peace process could not be restored "for many years", he said his comment "referred to the decommissioning issue".
There was need now to go back to the drawing board, identify mistakes and "see how we can restore confidence in the de Chastelain commission. We cannot do that unless we get a very clear statement from the British Prime Minister, the Taoiseach and the President of the United States making it absolutely clear this is an independent decommissioning commission.
Gen de Chastelain, with the support of the international community and the British and Irish governments, "should have been putting David Trimble in his place in relation to decommissioning, taking the whole contentiousness out of the issue and effectively getting on with his job", Mr McGuinness said.