The DUP leader, the Rev Ian Paisley, has said Northern Ireland has never been so close to a settlement as it is at the present time.
However, speaking in London following a meeting with the British prime minister Mr Tony Blair, Dr Paisley said Northern Ireland had to be "free from the scourge of terrorism" and that the IRA must hand in its weapons before a deal was reached.
Dr Paisley said he IRA must accept publication of photographs of the decommissioning of its weapons arsenal if it wants power-sharing restored in Northern Ireland.
He said there had to be clear proof that the IRA had given up its weapons if it wanted a deal on the restoration of devolved government.
"If you sin publicly you have to repent publicly," he told reporters outside No 10 Downing Street.
Today's meeting appears to be part of a final push for agreement on a deal to restore devolution to the North
The meeting comes as controversy grows over the proposed release of the four killers of Detective Garda Jerry McCabe as part of a deal with Sinn Féin to secure IRA decommissioning.
Mr Blair is expected to put pressure on Dr Paisley to sign up to a deal that will see the DUP share power with Sinn Féin in Stormont. The DUP made no comment to reporters as he arrived for the meeting in the last few minutes.
The deal appears to be in the balance, with the British and Irish governments awaiting formal responses from both the DUP and Sinn Féin to the blueprint they submitted last week.
Speaking before the Downing Street talks, the Sinn Féin leader Mr Gerry Adams called on Dr Paisley to agree to a deal.
"The question which must be asked and answered by Ian Paisley is: is he prepared to sign up to a comprehensive agreement which will have his party share power with Sinn Féin," the West Belfast MP asked. "Is it yes or no? "Is all of this going to be thrown away because Ian Paisley does not get the process of humiliation he wants?"
The 'humiliation' Mr Adams referred to is the photographing of actual decommissioning of IRA weapons, a major sticking point for republicans.
The two governments are hopeful they will be in a position to endorse a political agreement to restore devolution. Should this not materialise, they intend to publish details of the blueprint they offered to the parties.
Whatever the outcome of today's talks, it appears Mr Blair and the Taoiseach, Mr Ahern, will travel to Belfast on Wednesday.
The DUP main sticking point is IRA decommissioning. If the IRA addresses unionist demands for conclusive, transparent weapons decommissioning and an end to all violence, it is believed the Executive and Assembly could return in March.
This afternoon, the Minister for Justice said he is optimistic there could be a "huge step forward" in the next 72 hours in relation to the peace process. But Mr Michael McDowell said he will not speculate as to whether the killers of Det Garda Jerry McCabe will be released because the "preconditions" for such a release have not yet been met.
The Garda Representative Association, which is meeting in Adare, Co Limerick, to discuss their release, said it would seek legal advice on whether the convicted killers qualify for release under the Belfast Agreement.
The new executive would be see Dr Paisley as First Minister and Sinn Féin's Mr Martin McGuinness as Deputy First Minister.
The DUP would be expected to make a statement committing itself to power sharing and to working the political institutions properly including cross-border co-operation with the Government in Dublin.
It is also thought a deal would require republicans to start the process of signing up to new policing arrangements in Northern Ireland, with the British government committing itself to the transfer of policing and justice powers from Westminster to Stormont within two years.
Britain would also have to approve massive troop reductions in the North and the dismantling of army watchtowers and bases. The Taoiseach is understood to have agreed to give Northern Ireland's 18 MPs and three MEPs the right to participate in Dáil debates at least twice a year.
Additional reporting: PA
