The next six to eight weeks will be "critical" in determining the Northern Ireland peace process, Martin McGuinness has claimed.

Speaking to the BBC Radio 4 Today programme on Thursday, the Sinn Fein MP called on Ulster politicians to develop a "positive agenda" in the months leading up to May's elections to the Stormont assembly.

The ballot may be delayed, after former Northern Ireland secretary Dr John Reid suspended the assembly in October last year.

McGuinness argued that any delay in the elections "would be very damaging indeed."

"I think all of us at the heart of this process knows the best way to go forward is to try and resolve our problems over the course of the coming six to eight weeks and to move forward together with a very positive agenda into those elections," he said.

"It's going to require, I think, a collective approach over the course of the next six to eight weeks, which I think probably are the most critical six to eight weeks that we have seen in the course of the last 30 years."

He called on parties to give "leadership to the people rather than create a political vacuum," by developing a "positive and constructive frame of mind."

The leader of the Ulster Unionists, David Trimble, repeated calls for the IRA to renounce violence in the province.

"What has to happen is what should have happened, namely that there should be a giving up of violence for good, not temporarily, but for good," he said.

"That was what was in the agreement and that's what the agreement meant."