Officials from both governments met in London yesterday but were unable to build on progress made in earlier discussions on key issues. John Major and his Irish counterpart, John Bruton, had hoped to be able to launch the "twin-track" process with a summit before Mr Clinton arrives on Wednesday.
On Friday, Ireland's most senior civil servant, Paddy Teahon, flew to London with four colleagues for a meeting with British officials led by Sir Robin Butler, the Cabinet Secretary.
But sources indicated that progress made on one outstanding issue - British insistence that the security forces' arms are not regarded as equivalent to terrorist bombs and weapons - was "unpicked" yesterday afternoon.
They blamed the changed composition of the Irish delegation, which yesterday included officials from Dick Spring's foreign affairs department and justice department civil servants. Earlier meetings had taken place solely with Mr Bruton's civil servants. Mr Spring is seen in London as taking a harder line than Mr Bruton over disarmament; one source blamed "the hand of Sinn Fein" for the setback.
The other big issue is the remit of the international commission to be set up to assist the decommissioning. Britain insists that the Washington III condition - that the IRA begins decommissioning before talks begin - should be separated from the commission's remit.