The next three weeks are vital for breaking the deadlock in the peace process, the Northern Ireland Secretary has said.
Paul Murphy is hosting the talks at Stormont
Paul Murphy was speaking ahead of a fresh round of political talks on Wednesday.
The talks at Stormont, hosted by Mr Murphy, concentrated on issues arising out of a review of the Good Friday Agreement.
The Prime Minister's chief of staff, Jonathan Powell, held talks with Sinn Fein, the DUP and the Alliance Party.
Mr Powell has been closely involved in talks between Sinn Fein and the DUP throughout the summer.
The discussions are intended to pave the way for intensive negotiations to be chaired by the British and Irish prime ministers later this month.
However, DUP leader Ian Paisley insisted there would be no deal until the IRA was disbanded.
Mr Paisley arrived at Stormont to head the DUP delegation
Speaking after his meeting with Mr Murphy, Mr Paisley rejected suggestions that he was too ill to take an active role in the negotiations.
"All these other matters, essential as they may be if we are to have devolved government in Northern Ireland, cannot be discussed properly until we know that the rubbish has been removed," he said.
Mr Paisley also accused journalists of peddling lies about his health following a recent spell in hospital.
Sinn Fein President Gerry Adams said Mr Paisley's language was regrettable.
He said the real problem was that the DUP was anti-Agreement.
"This isn't just about getting the IRA out of the way, even if all of that was done," he said.
"They want to change what people voted for in two referendums on this island, so they have a big, big challenge."
Gerry Adams said the DUP was facing a "big, big challenge"
Speaking in Dublin on Wednesday, Irish Prime Minister Bertie Ahern said he believed it was essential that an agreement was reached before the next British general election.
The Taoiseach said it was not realistic to wait until then, if only because of the UK's presidency of the European Union which begins next January.
Mr Ahern also said the Irish Government was opposed to any changes to the system of electing Northern Ireland's first and deputy first minister.
Earlier on Wednesday, Paul Murphy said people wanted an end to direct rule.
"This is a different problem that we face, that the DUP is opposed to the Agreement and the other parties are in favour," he said.
"And yet, there are issues which are commonly held by all the parties.
"For example, the principle of consent is now common to everyone, the principle that you can't actually have an executive working in Northern Ireland unless it has upon it unionists and nationalists working together."
The political institutions in the province were suspended in October 2002 amid allegations of IRA intelligence gathering at the Northern Ireland Office.
The DUP and Sinn Fein have maintained high-level contacts with both governments over the summer.
A spokesman for Tony Blair said on Tuesday he believed there was a "shared agenda" between the parties which could lead to a deal.
The Ulster Unionist leader, David Trimble, will not be at Stormont for the talks as he is at the Republican Party convention in New York.
The Ulster Unionists withdrew from the review of the Agreement, saying the focus should be on ending paramilitarism, but they have now indicated they will take a full part in the main talks.
Mr Blair and Mr Ahern are to meet ahead of the intensive talks, it emerged on Wednesday.
A Downing Street spokesman confirmed the two prime ministers will hold a meeting, but insisted the date had not yet been finalised.