Sinn Fein President Gerry Adams has accused the DUP of pushing the North's power-sharing government toward crisis.
The West Belfast MP said the main unionist party's refusal to engage with his party on key issues was the root cause of the current political stalemate.
Sinn Fein and the DUP have held separate talks with the British Prime Minister in Downing Street this week amid reports that the power-sharing administration in Belfast has all but collapsed.
On Tuesday, a meeting of the Six County Executive, set for Thursday, was called off at short notice. Since Peter Robinson was elected DUP leader and First Minister in late May, only one meeting has been held of the multi-party Executive. The Ministerial cabinet is supposed to function as the North's devolved coalition government.
It is understood the meetings with the British PM focused on a long-standing issues, particularly the failure to transfer policing and justice powers from London to Belfast. Also at issue are the failure to pass legislation on Irish language rights, education reform and the conservation of the Long Kesh prison heritage site.
The cancellation of Thursday's meeting means ministers will not have held a formal round-table meeting for well over a month. Both the Assembly and Executive are not due to reconvene until September.
The SDLP has called for the Belfast Assembly to be recalled from its summer break to deal with the North's faltering economy, a call dismissed as "political posturing" by Sinn Fein.
Mr Adams laid the blame squarely for the deadlock at the door of "elements" within the DUP, which he claimed were only interested in forwarding their own narrow agendas.
"There are difficulties which need resolution if a crisis is to be avoided," he said.
"In early June the DUP committed to a process of negotiations to resolve all of the outstanding matters - and these go beyond the issues of the transfer of powers on policing and justice and an Irish language act.
"Essentially these are about getting, as required by the agreements, a fully functioning and cohesive government delivering on all issues which effect citizens in their daily lives on the basis of equality.
"The fact is that despite all Sinn Fein's efforts there has not been a proper engagement or process, and these issues have not been satisfactorily addressed."
Mr Adams called for "partnership government", which he said people had voted for.
"We are committed to a process of change as set out in agreements. Delivery of that process is crucial and will be the benchmark by which citizens will judge the work of the political institutions," he added.