"I do genuinely believe that we are within days of seeing an enormous change in the situation," Irish Prime Minister Bertie Ahern said on Wednesday.
Contacts intensified between Sinn Fein - the IRA's political ally - and the British and Irish governments this week following a weekend report that three senior Sinn Fein politicians had stepped down from the IRA's ruling Army Council.
That would pave the way for major structural changes in the Catholic, pro-Irish IRA, which fought a bloody, three-decade campaign against British rule until a ceasefire in 1997. Sinn Fein has asked the IRA to give up its weapons for good.
Irish Justice Minister Michael McDowell identified the men who stepped down from the Council as Sinn Fein President Gerry Adams, chief negotiator Martin McGuinness and Irish member of parliament and convicted gun-runner Martin Ferris. They have always denied belonging to the Army Council.
McGuinness travelled on Wednesday to the United States, traditionally a source of support for the IRA and Sinn Fein, adding to the speculation an IRA statement was imminent.
Speaking to reporters after arriving at Philadelphia International Airport, McGuinness said he was heading to Washington to brief politicians from the Republican and Democratic parties on the state of the peace process but would not comment on the content of any IRA statement, or McDowell's remarks.
"I do genuinely believe that we are within days of seeing an enormous change in the situation"
Irish Prime Minister
He acknowledged there were heightened expectations. "There's a lot of speculation. We haven't speculated. We have been patient and working hard to compel the Irish peace process forward. There will be huge challenges and huge opportunities lying ahead."
Sinn Fein called on the IRA in April to end its armed struggle after a series of high-profile crimes, such as the murder of a popular local man, caused international outrage.
A big bank raid in December 2004 and the murder of Belfast man Robert McCartney, both blamed on IRA members, has put Sinn Fein under intense pressure to disband the paramilitary group.
Leading Irish-American politicians snubbed Adams during his visit to the United States for St. Patrick's Day in March.
Any statement is expected to help kick-start stalled talks on Northern Ireland's political future, although resolution is still seen as a long way off given traditional enmity between Protestants, who favour continued union with Britain, and Roman Catholics, who want an end to British rule and a united Ireland.
Violence persists in northern
Talks on reviving an assembly, set up under the 1998 Good Friday Agreement and in which Catholics and Protestants together ran the province's affairs, broke down at the end of last year.
Dublin and London say IRA crime is hindering progress. Sinn Fein's main opponents, the Protestant Democratic Unionist Party, refuses to sit in government with the Catholic party until the IRA publicly disarms.
Although the bombs and shootings that claimed more than 3,600 lives during the "Troubles" have largely ended, violence in Northern Ireland persists as "punishment" beatings, stabbings and killings as communities try to control their own members.