The IRA is not the problem in the negotiations aimed at breaking the political stalemate, Sinn Fein's chief negotiator has said.
Mr McGuinness said Agreement was an international treaty
Martin McGuinness said tensions within the Democratic Unionist Party were proving to be the problem.
Speaking on the BBC's Inside Politics programme, he would not be drawn on the details of the IRA's contribution to the process.
The DUP and Sinn Fein held further meetings on Saturday on the British-Irish proposals to break the political stalemate.
Mr McGuinness said the British and Irish proposals were, broadly speaking, the government's best guess for a resolution.
And he said the challenge for the DUP leader Ian Paisley was to show confidence - and deliver his party before the election.
"There is considerable satisfaction, in my view, within the process, within the key negotiators in all of this that the IRA are not the problem at this particular time," he said.
"The problem at this particular time, is whether or not the Democratic Unionist Party are going to make up their minds as to whether or not they are going to do the business, and do the business now."
Another problem was whether the British and Irish Governments were "absolutely committed to the faithful implementation of an Agreement which after all is an international treaty", he said.
Mr McGuinness refused to say whether he would personally recommend to the IRA that church witnesses be allowed to view decommissioning.
Irish Prime Minister Bertie Ahern said on Saturday he believed there was a very real prospect of the whole island of Ireland having an historic and peaceful Christmas.
The British and Irish Governments were committed to doing everything they possibly could in the coming days to resolve all the outstanding problems in the political process, he said.
Mr Ahern said he was upbeat about the prospects for a breakthrough.
However, while the parties continue to consult and negotiate, Irish Foreign Minister Dermot Ahern earlier warned time was running out.
The British and Irish Governments want an answer from Ian Paisley and Gerry Adams by the end of the month.
In Dundalk in County Louth, Sinn Fein's Mitchel McLaughlin addressed the party's councillors on Saturday.
He said: "Of course, there are still issues that have to be effectively addressed and
resolved. That is the focus of our ongoing discussions with the two governments.
"We believe that this can be done if the governments are genuinely committed
to the Good Friday Agreement. And we see no reason why all of these matters
cannot be sorted out by the end of next week.
The DUP assembly team are drawing up their own detailed analysis of the outstanding issues.
The DUP leader Ian Paisley and members of his talks team left Stormont on Saturday afternoon following a meeting.
The SDLP leadership briefed its councillors' association on Saturday.
Association chairman Pat Mallon said: "The SDLP councillors stand full square behind the leadership and the Good Friday Agreement."
The DUP's executive will meet next Friday night.
The DUP wants to know the IRA is committed to the proposals outlined by the government.
Sinn Fein and the DUP are holding further meetings
Sinn Fein is demanding the proposals reflect more fully the Good Friday Agreement.
On Friday, the DUP's assembly team said significant progress had been made since September's intensive talks.
The British and Irish Governments put their proposals to the DUP and Sinn Fein, the main unionist and nationalist parties in Northern Ireland, on Wednesday.
The plans followed two months of continuing negotiations aimed at exploring a way around the stumbling blocks faced at September's talks at Leeds Castle in Kent.
As the leaderships of Sinn Fein and the DUP briefed assembly members on Friday, Sinn Fein urged the DUP to talk directly to them about the governments' proposals.
The DUP's assembly team was briefed at Stormont on Friday by party Mr Paisley about the state of the current negotiations to restore devolution.
After the meeting which lasted more than two hours, the 33 assembly members said in a statement: "Members recognise that significant progress has been made in the days and weeks since Leeds Castle and that there is still work required."
'Future paramilitary activity'
Both parties still have concerns, but there is cautious optimism that a resolution is possible.
After two years of stalemate, Stormont remains suspended, but signs are emerging that it could be back in business within months.
More meetings are expected in Downing Street in the next few days.
At the conclusion of intensive political talks at Leeds Castle in Kent in September, Mr Blair and Mr Ahern said the thorny issues of IRA disarmament and future paramilitary activity appeared to be resolved.
But, the two governments were unable to get the Northern Ireland Assembly parties to sign up to a deal over power-sharing after unionists and nationalists clashed over future devolved institutions.