The DUP has dismissed the British-Irish Intergovernmental Conference as a “talking shop”.
Nigel Dodds MP was speaking after it was announced that the body will meet next month for the first time since 2007.
It is being revived amid efforts to restore power-sharing at Stormont.
Mr Dodds said: “It doesn’t have any powers, purely consultative, and it really is a talking shop because it can’t deal with devolved matters in Northern Ireland.”
However the move has been welcomed by Sinn Féin.
The party’s Stormont leader, Michelle O’Neill, said: “It’s written down in the Agreement, it’s what has to happen in the absence of an Executive.
“I think it is significant that it’s going to happen, but clearly it needs to be very strong in what it does, so that’s the obvious next question: what is it going to do?
“The two governments, when they come together, have a moral obligation as co-guarantors of the Good Friday Agreement, to try and restore the institutions.”
The conference will take place in London on 25 July.
While the Cabinet Office did not mention the power-sharing impasse in a statement announcing the initiative, instead describing the focus as "East West issues", Ireland's deputy premier Simon Coveney said "Northern Ireland issues" would be on the agenda.
Cabinet Office Minister David Lidington and NI Secretary Karen Bradley will attend.
Taoiseach Leo Varadkar suggested the conference could also help ministers keep in touch after Brexit.
“While we see each other all the time, ministers meet their counterparts, I meet the Prime Minister four or five times a year here in Brussels,” he said.
“After the UK leaves the EU those interactions may not necessarily happen any more.
"So we need an alternative mechanism to do that and I think the BIGC could potentially be the mechanism by which we continue to cooperate and stay close.”