Sinn Féin and the Democratic Unionist Party will be the two dominant parties in Northern politics for at least the next 10 years and should be in talks now, Mr Martin McGuinness has declared.
Speaking before a meeting in Leinster House yesterday with the Minister for Foreign Affairs, Mr Cowen, the Sinn Féin chief negotiator urged the DUP to hold direct talks.
His party continues to press the DUP for talks aimed at the restoratio of Stormont, but the DUP says it will not negotiate unless the IRA is stood down.
With Sinn Féin frustration at the current stalemate growing, Mr McGuinness said: "As everybody knows, as a result of the recent elections the political landscape of the North is probably going to see the dominance of the DUP and Sinn Féin for at least the next 10 years.
"There is no escaping the need for Sinn Féin and the DUP to work together in conjunction with the two governments," said Mr McGuinness, who called the DUP's refusal "now almost ludicrous".
Urging all sides to engage over coming weeks, he added: "If there is to be a political breakthrough in September then the work needs to be done now."
His remarks followed comments by Senator George Mitchell in Belfast that the British and Irish governments cannot force the parties in Northern Ireland into agreement.
Senator Mitchell, who chaired the negotiations leading to the Belfast Agreement in 1998, was in Belfast in his capacity as Chancellor of Queen's University.
He accepted that the British and Irish governments could not make the parties agree, but they had to make it clear that the present uncertainty had to be resolved, he said.
"I can't tell you when or how. I'm not involved in the day-to-day discussions that have gone on and I understand will resume in September," he said.
"But I think there is a widespread recognition that this is a different time and a different place, and that the people are looking forward to a future that is hopefully prosperous, tolerant, free of violence and one in which the people of Northern Ireland can govern themselves.
"That's a tall order for the political leaders given the difficulties of the past, but I think that's the mandate that they have."
Responding, Mr McGuinness said the former US senator was "right, up to a point.
"All of us recognise at this time that it is vital and essential that the DUP are told very forthrightly by the two governments that as the lead party on the unionist side they have a responsibility."
Mr McGuinness welcomed last week's call on the DUP by President Bush's special envoy, Dr Mitchell Reiss, "to be involved in meaningful discussions with all of the parties, including Sinn Féin".
Mr McGuinness said: "I remain open to be convinced that the DUP intend to approach all of this in a positive frame of mind.
"My hope is that they will, that they will recognise that there is a mighty responsibility on the two governments, the parties to break the impasse.
"The key to all of this is to do the work now. There is no point in us going on holidays. We must buckle down to the job in hand, so that the work in September can deliver."
He went on: "We have a right to expect, if the DUP don't come up to the plate, that the governments must recognise that there are all sorts of outstanding matters that they can proceed with."
The British and Irish governments are to set aside several days for the talks with the parties in September.
These will be aimed at attempting to resolve four ongoing issues: paramilitary activity, decommissioning, the suspended institutions and policing. Mr Gerry Adams of Sinn Féin is to meet the Taoiseach in Dublin today.