Sinn Fein's chairman, Mr Mitchel McLaughlin, has warned that the coming fortnight will be a critical period in the peace process.
Mr McLaughlin stressed the need to maintain momentum in the current talks in Belfast, but conceded that "at the moment it's not looking good".
He said he presumed that the UUP leader, Mr David Trimble, would not be "too adventurous" in advance of his party's annual conference next Saturday, but added that "if we can get the groundwork done now we can all have the confidence that this is going to sort itself out".
Mr McLaughlin was speaking after an Irish independence rally organised by Sinn Fein's youth wing, Ogra Shinn Fein, in Dublin yesterday. Up to 300 people took part in the march, ending in a rally outside the GPO in O'Connell Street which was addressed by Mr McLaughlin.
The demonstrators had a large cardboard model of an RUC Land-Rover painted with the slogan "Disband the RUC". Other rally participants wore Ku Klux Klan-style masks in orange fabric, a reference to Orangemen.
Ms Brenda McCabe, an Ogra Shinn Fein member from Co Fermanagh, said the organisation wanted the release of all republican prisoners, "real action" on the drugs crisis and the complete disbandment of the RUC, not the "cosmetic changes" in the recent Patten report on policing.
Speaking after the rally, Mr McLaughlin said that at today's meeting between the Sinn Fein president, Mr Gerry Adams, and Mr Trimble, his party would encourage the UUP leader "to keep moving and moving in the right direction".
He said that if the condition of prior decommissioning was attached by Mr Trimble to setting up the political institutions, then he would be contradicting the Belfast Agreement.
"We have to get back on to the agreed agenda and people can read that agenda for themselves and make their own minds up. It's no good saying to us `David Trimble's in trouble. Can you help him out?' It's not our responsibility.
"We made an agreement with somebody and we knew that there were problems in unionism and when it came to the referendum almost 50 per cent of unionism voted against it. That's a reality.
"But what has David Trimble's leadership given us? He has more problems now than he had then. He hasn't consolidated his position. He hasn't built on the support that he got for the Good Friday agreement, and all of us are now feeling the frustration and the disappointment at the failure to set up the political institutions, at the failure to implement the Good Friday agreement."