Northern Ireland First Minister David Trimble has warned that direct rule will resume if IRA decommissioning has not begun by the end of the month.

But speaking on the BBC Radio Ulster's Inside Politics programme, the Ulster Unionist leader said the move was a price worth paying.

Mr Trimble's comments come a day after he warned that devolution could be suspended unless there was a move on the handover of IRA weapons by the end of January, but he urged people not to panic over this "crisis".

Sinn Fein accused the Ulster Unionists of setting a new deadline beyond the terms of the agreement.

Speaking on Saturday, Mr Trimble said he hoped there would be progress on decommissioning but could not be sure of a positive outcome.

"If things don't work out as we had hoped and if it proves impossible to sustain the administration in its present form, the only immediate recourse is direct rule," he said.

"And the only way of carrying on the political process is some form of review in the circumstances that then obtain."

Ruling council

Mr Trimble will face his party's ruling council on 12 February to review a decision to go into government with Sinn Fein before IRA decommissioning.

The council endorsed the Mitchell peace deal last November which allowed devolution to take place prior to the handover of terrorist weapons.

The assembly's new power sharing executive took up its reins in December, ending 25 years of direct rule from Westminster.

But Mr Trimble has pledged that he and his executive colleagues will resign, and collapse the institutions of government, if arms decommissioning has not started by the end of January.

That is when Canadian General John de Chastelain, who heads the decommissioning body, is to give a crucial progress report on illegal arms.

BBC NI Political Editor Stephen Grimason said even if there was another crisis over decommissioning, the first minister thought things would work out "in the long term".

Mr Grimason added: "But republicans say they never made any promises on IRA weapons.

"And any attempt to blame them for lack of movement on the issue by suspending the institutions would be fought tooth and nail."

But the Ulster Unionist deputy leader says his party will begin to bring down the executive within nine days if no proof emerges that the IRA is disarming.

John Taylor told BBC Radio 4's Today programme: "We must bring the executive to an end if the IRA have not honoured the Belfast Good Friday Agreement."

He said he did not want to see the executive suspended, but the entire Good Friday Agreement needed to be implemented.

However, Sinn Fein assemblyman for North Belfast, Gerry Kelly, said it would be "untenable" for unionists to end the political process at a time when the IRA was on ceasefire.

He insisted that it was for General de Chastelain and the armed groups, not the politicians - including Sinn Fein - to determine how to deal with the issue of decommissioning.

Mr Kelly told the BBC: "To talk about pulling the executive down when the guns have been silent for such a long time and continue to be silent, for republicans and nationalists is very hard."

The issue of decommissioning is the final piece of the jigsaw of institutions to be set up under the terms of the 1998 Good Friday Agreement.

The peace deal, brokered by former US senator George Mitchell, broke the deadlock in the stalled peace process.