The DUP has called on Northern Ireland Secretary Peter Hain to resign after he said the economy was "not sustainable in the long term".
The DUP has called on Peter Hain to resign
Mr Hain told the New York weekly newspaper the Irish Echo, that "the island of Ireland should in future be marketed as a single entity".
DUP assembly member George Dawson said Mr Hain should resign.
The row came as the DUP met Irish Prime Minister Bertie Ahern in Dublin on Friday.
Mr Dawson, who described Mr Hain's comments as "disgraceful and insulting, inaccurate and unjustifiable," added that his role was to build confidence in the Northern Ireland economy.
"Speaking in America, the secretary of state has done inestimable damage to the Northern Ireland economy," Mr Dawson said.
"And rather than the Northern Ireland economy being unsustainable, I rather think it is the secretary of state's position which is unsustainable at the moment."
A DUP delegation led by party leader Ian Paisley held talks with Bertie Ahern and Foreign Minister Dermot Ahern.
Speaking after the hour-long meeting, Mr Paisley described the talks as "forthright".
He said he warned the Irish government of the implications of allowing MPs from Northern Ireland to speak in Leinster House.
The DUP leader added that he had also raised his concerns about the continued presence of the three Irish men accused of training FARC guerillas in Colombia in the Republic.
The DUP refused to take part in talks with the Irish and British governments on Monday, jointly hosted by Dermot Ahern and Mr Hain.
The party said it was not taking part as the talks seemed to be nothing more than stock-taking.