Northern Ireland's Deputy First Minister Martin McGuinness has said Sinn Fein has fulfilled its obligations in government and now wants unionists to do the same to avoid a political crisis.

With the region's power-sharing government on the verge of possible collapse, his comments came as he prepared to enter a crunch meeting with Democratic Unionist Party (DUP) leader Peter Robinson.

The British and Irish Premiers are holding talks in London on Monday on the growing crisis as the DUP and Sinn Fein seem unable to agree a deal on devolving policing and justice powers from Westminster to the Assembly.

Mr McGuinness claimed that, while his party had backed new policing structures after the 2006 St Andrews agreement which paved the way for power-sharing, the DUP had yet to fulfil its commitments.

"Within three months of the St Andrews agreement we in Sinn Fein moved forward decisively on the issue of policing, took what was considered to be an historic and monumental decision," he said.

"And we did that within three months of St Andrews... to ensure that these institutions would work.

"Three years on, three years on, we are waiting for the DUP to deliver and honour their commitments, that all of us were supposed to have signed up to under the terms of an agreement that was presided over by the Irish Government and the British Government."