Sinn Fein's president has said there will be no IRA activities which will undermine in any way the Northern Ireland peace process.
Gerry Adams questioned whether obligations would be met
Gerry Adams made the comments on Wednesday in response to the prime minister's call for assurances on the IRA's future intentions.
Tony Blair said a statement from Mr Adams at the weekend that "there should be no activities inconsistent" with the Good Friday Agreement did not go far enough.
The prime minister wanted the word "should" changed to "will" - the word the Sinn Fein leader used in Wednesday's news conference in Belfast.
Mr Adams said: "I want now - in the interests of moving matters forward - to eliminate any doubt that might exist.
"The IRA leadership makes it clear in its statement that it is determined that its activities will be consistent with its resolve to see the complete and final closure of the conflict.
Tony Blair said he wanted a straight answer from the IRA
"Furthermore, the IRA leadership is determined that there will be no activities which will undermine, in any way, the peace process and the Good Friday Agreement."
In response to the West Belfast MP's comments, a Downing Street spokesman said the prime minister wanted to know "if the statement meant punishment beatings, exiling, arms procurement and development, intelligence gathering and targeting are at an end?"
Meanwhile, Ulster Unionist leader David Trimble has met Mr Blair at Downing Street as efforts continue to reach an agreement to restore devolution to Northern Ireland.
Speaking after the talks, Mr Trimble said it had been a positive meeting but he did not expect a quick resolution to the political difficulties.
Reacting to Gerry Adams' statement, Mr Trimble said:
"It would be so easy for Mr Adams, when asked is there going to be an end to all paramilitary activity, it would be so easy for him to say yes.
David Trimble said that Mr Adams' statement was not enough to move the process forward
"The fact that at the second or third time of asking he has been unable to give a clear answer on this is illustrative of the underlying position."
However, sources within the Irish Government have described Mr Adams' statement as another significant development in the process of confidence building in the peace process.
It is understood the Taoiseach, Bertie Ahern, will speak with Mr Blair later on Wednesday.
The SDLP have called for the publication of all recent publications and clarifications between the various parties relating to the political process.
Assembly member Alex Attwood described Gerry Adams' statement as another step forward and called for the two government's proposals for progress to be made public in order to eliminate public confusion about the state of the process.
Although campaigning is under way, elections to the assembly on 29 May are in doubt because there is no agreement on a return to power-sharing.
Northern Ireland's power-sharing administration was suspended on 14 October 2002, amid allegations of IRA intelligence gathering at the heart of the Stormont government.
Speaking in the Commons on Wednesday, Mr Blair told MPs the situation in Northern Ireland was "fraught and difficult".
He said: "There is no question of reconstituting the government in
Northern Ireland unless undertakings are clearly given and followed by action."
Meanwhile, anti-Agreement DUP MP Nigel Dodds dismissed Mr Adams' statement as "yet more hollow words".
"It is a cynical election stunt which will fool no sensible unionist in Northern Ireland," he said.
If the election date is changed, new legislation would have to go through the House of Commons.
Earlier this month, the British and Irish Governments said they were postponing publication of their blueprint to fully implement the Good Friday Agreement and restore the institutions until the IRA had answered questions about a statement it submitted on 13 April.