Democratic Unionist leader Ian Paisley has held what he has described as a ``very constructive'' meeting with Irish Prime Minister, Taoiseach Bertie Ahern.
Thursday's meeting in London, described by some as ``historic'', came ahead of the opening session of the review of the 1998 Good Friday Agreement on 3 February.
The review will involve the British and Irish governments and parties elected to the Belfast assembly last November. The DUP are seeking to renegotiate the Agreement during the process which could last until Easter, something which is bitterly opposed by nationalists.
The DUP's five MPs accompanied their leader to the meeting at the Irish Embassy in London. It was the first such meeting between a DUP leader and an Irish premier.
Asked if he could do business with the Taoiseach, Mr Paisley said: ``I can do business with any man who is prepared to face up to the issues. Today I think there was a facing up, perhaps in a new context, with these issues.''
Mr Ahern said they both wanted to see progress in the peace process and ``the end of the guns in Northern Ireland''. But he insisted the review would look only at the operation of the 1998 Good Friday Agreement and that ``the fundamentals are not up for negotiation''.
He said he hoped contacts with the DUP would be broadened over the coming weeks.
Mr Paisley said he reminded the Irish government that the forthcoming Good Friday Agreement review had to be about finding a deal that unionists as well as nationalists can support.
He said the DUP had told the Taoiseach that his party would not be negotiating with them on matters relating to the internal structures of how the Six Counties was governed. He wanted to see see the creation of ``good neighbourly relations'' with the 26 Counties.
Sinn Féin president Gerry Adams welcomed the meeting. However, the West Belfast MP said during a visit to Galway that Mr Ahern and his colleagues had to ``defend, promote and implement the Agreement and stand firm against those who would seek to destroy it''.
Mr Adams continued: ``Let there be no appeasement of the DUP`s position, which is built on exclusion, precondition and a desire to end the Agreement.
``The people of this island voted overwhelmingly for the Agreement, and in the 26 Counties the constitution was changed to facilitate it.''
The Sinn Féin leader also welcomed the DUP's participation in the review of the Good Friday Agreement.
But he insisted Mr Paisley's party could not exercise a veto during the review .over rights and entitlements of citizens''.
``What it can have as a birthright the same as the rest of us is equality - nothing more, nothing less.''
Mitchell Reiss, who was announced last December as the replacement Ambassador Richard Haass, is expected to be ratified this weekend as the President's new peace process envoy.
He is due to arrive in Belfast on Monday where he will meet politicians taking part in the review which begins next Tuesday. US officials said Dr Reiss would be ``in a listening mode''.
Gerry Adams became the first Irish Ireland leader to meet Dr Reiss during a visit to Washington last week.