Talks with Gordon Brown and the Irish government in London are scheduled for Friday, after Mr Robinson assumed the First Minister's position from the Rev Ian Paisley.

Handing down responsibilities for policing and justice to a local minister and divisions over an Irish language act have divided Sinn Fein and the Democratic Unionist Party (DUP).

Mr Robinson, DUP leader, said: "We have exercised our veto and we have not been alone in applying a veto. It isn't an indication of strength or success, it is simply an indication that we were unable to agree.

"My colleagues and I didn't negotiate these changes as a weapon to be used against other parties but as a safeguard for as long as it is needed of the interests of everyone in Northern Ireland."

The DUP believes there isn't community confidence at present to devolve security powers. Sinn Fein insists it was a commitment of the 2006 St Andrews Agreement, which paved the way to political power-sharing.

Sinn Fein deputy first minister Martin McGuinness said: "The war is over. We need to start talking to each other and not at each other.

"We as political leaders must take the lead, particularly here in this chamber. I believe that despite all of the challenges which lie ahead we can continue to make progress."

Irish Foreign Affairs Minister Micheal Martin sent his congratulations to both Mr Robinson and Mr McGuinness.

Alliance leader David Ford said the glowing words of the DUP and Sinn Fein did not reflect reality. Nationalist SDLP leader Mark Durkan said there had been phoney uncertainty around the Assembly's future.