The entry of Sinn Fein ministers into the Northern Ireland executive could lead to a new split in the republican movement by hardline members, according to the First Minister and UUP leader, Mr David Trimble.
Mr Trimble said he had been told that following the defection last year of those who formed the "Real IRA" and the 32-County Sovereignty Movement, "another group is teetering on the brink of defection" at the prospect of Sinn Fein ministers in a Northern Ireland government, but they were "doctrinaire republicans" who might break away anyhow.
Mr Trimble, who was briefing a small number of influential US columnists and The Irish Times after his arrival in Washington, said he was looking for "just the beginning of the process of decommissioning" of IRA arms and would be happy to leave the mechanics to General John de Chastelain. But "if we don't get some movement" on decommissioning, "support for the agreement will collapse" among the unionist community.
Mr Trimble said he had discussed with Mr Gerry Adams and Mr Martin McGuinness of Sinn Fein the possible "choreography" of decommissioning and how it could be co-ordinated with the formation of the executive so as to give republicans confidence "that something will happen". This could be done "in 48 hours or even squeezed further if possible".
He has not had "a favourable response so far" from the Sinn Fein leaders but he would be meeting Mr Adams in Washington on Wednesday, Mr Trimble said.
He said he had told Mr Adams that he does not believe him when he says he cannot persuade the IRA to begin decommissioning at this time. Mr Trimble said that he assumes Sinn Fein/IRA will play this "down to the wire" and delay any move on decommissioning until the last moment.
This is because they will want to prevent dissident republicans trying to block any move on arms. But he believed the IRA leadership has "made its dispositions to ensure it keeps control", such as the appointment of a new chief of staff.
Mr Trimble said he knew that President Clinton wanted to be helpful in the decommissioning impasse. He believed that the White House was being "helpful behind the scenes" in this matter.
The British Prime Minister, Mr Blair, last night briefed President Clinton by telephone on the situation in Northern Ireland, ahead of the President's meetings with leading politicians later this week. Mr Blair told Mr Clinton he could have "a real influence" on the peace process, a Downing Street spokesman said. Mr Clinton said he would do "whatever he could", the spokesman added.
Mr Blair emphasised that the peace process was entering a "vital phase" and it was important that the three governments - London, Washington and Dublin - worked closely together, the spokesman said.
Concerning his own position as UUP leader, Mr Trimble said the pro- and anti-agreement unionists in the Assembly were now split 29 to 29. "Technically I could continue if I dropped one or two more members, but morally I would be defeated and could not carry on much longer," Mr Trimble said.
In New York Mr Trimble said an equality office set up as part of the new Northern Ireland government would probably be led by a representative of the nationalist community and would ensure fair treatment and equal opportunity to both communities in the province.
A junior minister appointed to head the unit should come from the SDLP, he said. It would operate out of the office of the First Minister and Deputy First Minister to build confidence so each community would feel it received fair treatment. The unit would act in a supervisory role monitoring policies, Mr Trimble said.
Mr Trimble said he was also committed to dealing with the jobless in both Catholic and Protestant communities.