"A man has been murdered at the hands of those linked to a party of government," Robinson said in a statement on Monday, referring to the murder of former IRA member Kevin McGuigan on August 13.

The minister emphasized that his Democratic Unionist Party (DUP) was unwilling to continue "as if nothing had happened."

"If it becomes apparent to us that a satisfactory resolution in the talks is not possible, then… as a last resort ministerial resignations will follow," Robinson added.

Irish and British representatives were meeting on Tuesday to discuss possible solutions to the present crisis.

On Monday, the pro-British Union Ulster Party (UUP) declared it was leaving the coalition. The only minister from the party will give up his position in the regional government next week, party leader Mike Nesbitt said.

The latest controversy centers on the death of Kevin McGuigan, a former IRA militant. The murder raised fears that the group was still operating in secret.

Officials investigating the killing at the time said the IRA's structure "remains broadly in place," but the IRA was "no longer engaged in terrorism."

However, McGuigan's death, including a string of paramilitary attacks before the fatal incident, led members of the coalition to accuse Sinn Fein of being dishonest of the IRA's existence.

The Sinn Fein is the political arm of the IRA, which waged a violent movement to drive Britain out of Northern Ireland. In 1998, representatives of London and Belfast signed deal called the "Good Friday agreement" to end a decade-long conflict that killed around 3,500 people.

mg/jil (dpa, AFP)