Sinn Fein's deputy leader Martin McGuinness told Britain's Sky Television on Sunday that it was totally opposed to any return to conflict between Irish nationalists and the British government.
When pressed on whether he would "categorically" tell Republican paramilitaries and the Provisional IRA not to break the ceasefire, McGuinness said he would tell all parties to avoid violence.
He urged every side, including the Republican movement, the Loyalist parties, the British army and even "undercover elements" in the British military to resist taking any actions that could jeopardise the peace process.
Efforts to forge a political settlement between the British-ruled province's feuding Catholic and Protestant communities ground to a halt in December after a $50 million bank heist Britain and Ireland blamed on the IRA.
Last week the outlawed guerrilla group withdrew a conditional offer to put its weapons beyond use, although the statement did not explicitly threaten to end its 1997 ceasefire.
A $50 million bank robbery has
hurt the Ulster peace process
McGuinness said the political stalemate would not be broken by fresh unrest.
"We believe the peace process is the best way forward," said McGuinness, who along with leader Gerry Adams is regularly accused of being a member of the IRA's ruling seven-man "Army Council". Sinn Fein has always denied this.
The British and Irish governments have said they do not believe the withdrawal means the IRA is preparing to plunge the province back into the violence that has cost 3600 lives over 30 years.
Although the killings have largely stopped in Northern Ireland, politics have been deadlocked since 2002 when a regional government set up to share power between Protestants, who mainly support British rule, and Catholics, who mostly want a united Ireland, broke down.
Britain and Ireland have heaped criticism on the IRA, saying its refusal to give up paramilitarisim and crime are to blame for the failure in efforts to return the province to self-rule.