Time is running out for the IRA to decommission its weapons and restart the peace process, the Northern Ireland secretary has warned.

Dr John Reid said on Sunday progress must be made by midnight on Thursday following UUP leader David Trimble's decision to withdraw his ministers from the Stormont executive.

He warned that if the deadline passes without a positive step from the IRA, Reid will have to decide whether to suspend devolution or call fresh elections to the Northern Ireland Assembly.

"Everybody knows what we have to do. We have very little time indeed now to do that. We are fast running out of time on this impasse," he said.

There have been a series of hints from the IRA throughout last week that it is ready to make the decommissioning move. Its senior commanders could be set to pour concrete into one of its major arms dumps - a method of decommissioning accepted by General de Chastelain who is overseeing the process.

Sinn Fein leader Gerry Adams replied to the Northern Ireland secretary's warning by saying the IRA's move towards decommissioning arms would be done to save the peace process.

"If the IRA is persuaded to make some move on this issue, it will because it wants to rescue the process. We have told them that we will continue to try with others to create a context into which the IRA and others may wish to step. The decision has to be theirs," he said."There is nothing in the process, there is nothing in the way it is being worked that is binding upon the IRA, or the IRA leadership. In fact, the process is being worked in exactly the wrong way.''

He revealed his party was currently engaged in talks with London, Dublin and the other Northern Ireland parties which would continue "at least until tomorrow". Adams added there also had to be progress on the weapons held by the loyalist paramilitaries as part of any solution.

"Sinn Fein's endeavour is to create a political context which stabilises the process and which makes it sustainable. But we are working in very, very difficult circumstances. Our view is very clear: we want to see the guns taken out of Irish politics. The focus has been only on the silenced guns of the IRA. There has been no focus worthwhile on these other guns, which are almost in daily use," he said.