Politicians are waiting to see if the IRA will respond to pleas from Gerry Adams to abandon violence and embrace the Northern Ireland political process.
Opponents of Sinn Fein say they want action from the IRA
The Sinn Fein leader said the climate was now right for the IRA to "fully embrace and accept" democratic means.
Downing Street said the statement was "significant" but opponents say they want IRA action, not Sinn Fein words.
Republicans have been under pressure since the £26.5m Northern Bank raid and the killing of Robert McCartney.
US Senator Edward Kennedy also refused to meet Mr Adams during St Patrick's week celebrations because of the IRA's "ongoing criminal activity".
Mr Adams said the IRA had "kept every commitment made by its leadership" but the struggle had "reached a defining moment" and he appealed for members to move forward.
He said the text of his statement had been given to the leadership of the IRA.
"For over 30 years, the IRA showed that the British government could not rule Ireland on its own terms," he said.
"You asserted the legitimacy of the right of the people of this island to freedom and independence.
"Many of your comrades made the ultimate sacrifice. Your determination, selflessness and courage have brought that freedom struggle forward towards its attainment."
'Bend the knee'
Mr Adams said that in the past he had defended the right of the IRA to engage in armed struggle.
"I did so because there was no alternative for those who would not bend the knee or turn a blind eye to oppression or for those who wanted a national republic. Now there is an alternative.
"The way forward is by building political support for republican and democratic objectives across Ireland and by winning support for these goals internationally."
SDLP leader Mark Durkan said it appeared Mr Adams had begun to accept that there was no reason for the IRA to exist, but the statement may have been an attempt to ease the pressure on Sinn Fein.
"That's why it is action from the IRA that counts - not words from Sinn Fein," he added.
DUP leader Ian Paisley said: "The unionist population have proved him in the past to be an absolute deceiver and a liar and this is just another political stunt promoting himself as a democrat."
Ulster Unionist leader David Trimble said: "If republicans wish to be included in talks then they must rebuild their credibility by doing all the things they should have done and present themselves as a purely peaceful democratic movement with no private army."
Shadow Northern Ireland spokesman David Liddington said people needed to see evidence of permanent change within the republican movement.
"Trust can only be built on actions, not just words," the Conservative spokesman said.
Fine Gael leader Enda Kenny said he believed Mr Adams was engaging in electioneering.
"I would suggest that if Gerry Adams wants to lead by example, he should now remove the Sinn Fein party from its connection with the IRA which has proven to be a gang of criminals involved in bank robberies, criminality and murder," he said.
Talks last year failed to restore devolution, which stalled amid claims of IRA intelligence gathering at Stormont in 2002.