The Northern Ireland Secretary, Dr John Reid, described yesterday's comments from Sinn FΘin on IRA arms decommissioning as "highly significant" and he called on paramilitaries to respond positively.
Meanwhile, Downing Street said the speech by Sinn FΘin president Mr Gerry Adams was "very welcome".
Dr Reid said the comments were a "highly significant statement from someone of Gerry Adams's authority and stature within republicanism".
"Like everyone I hope that the IRA will accept the view that a ground-breaking move on the arms issue will transform the situation," Dr Reid said.
Earlier, Dr Reid had met Mr Adams at Stormont, where he signalled that if the IRA and loyalist paramilitaries moved on arms decommissioning the British government's response, and indeed the response of the wider international community, would not be "grudging or onerous".
Meanwhile, the Shadow Northern Ireland Secretary, Mr Quentin Davies, said that any move on IRA decommissioning had to come within the next 48 hours in order to save the political institutions in Northern Ireland.
"Clearly if Gerry Adams's speech is genuinely followed by a real act of decommissioning that will be very welcome," Mr Davies said. "Whatever the IRA does is likely to be just the first step in a decommissioning process that under the Belfast Agreement should have been completed 1 1/2 years ago."
Mr Davies said it was "absolutely vital" that full decommissioning must take place on both sides of the community, otherwise there would never be lasting peace. "It is absolutely vital that full decommissioning takes place on both sides. The so-called loyalist paramilitaries must now match any IRA decommissioning, and the IRA must themselves continue the process. Otherwise there can never be peace in Northern Ireland."