Gerry Adams made the comments to the BBC
Republicans need to be prepared to remove the IRA and the issue of IRA arms as an excuse for unionists to block political progress in Northern Ireland, Gerry Adams has said.
But the Sinn Fein president said the republican leadership would only be empowered to do that if there was a context in which they could make progress.
Speaking to the BBC on Wednesday, Mr Adams said he did not see the IRA doing that of its own volition but only as part of an "ongoing process of sustainable change".
He said if there was not such a process then there "would be great difficulties".
"I personally feel that while there are justifiable fears within unionism about the IRA and while people have concerns about the IRA, I think political unionism uses the IRA and the issue of IRA arms as a excuse," he said.
"I think that republicans need to be prepared to remove that as an excuse.
"But we who are in leadership will only be empowered to do so if there is a context in which we can make progress."
The political institutions in the province were suspended in October 2002 amid allegations of IRA intelligence gathering at the Northern Ireland Office.
The issue of ongoing paramilitary activity remains a major obstacle to restoring devolution with Northern Ireland's largest party, the Democratic Unionists, adamant that the IRA must wind down if they are ever to share power with Sinn Fein.
Democratic Unionist assembly member Ian Paisley Junior said it was actions from the IRA, not Mr Adams' words, that counted.
The North Antrim MLA said: "Mr Adams and the IRA need to come to terms with the fact that unionism will
not accept anything less than serious, substantial and conclusive action from
"Yes we do have justifiable fears about the IRA and they must be assuaged."
Mr Paisley said the IRA and its stockpile of weapons and involvement in
criminal activity and paramilitarism must disappear, "not just because it was a
demand for unionists".
He said all those elements had to disappear because it was the right thing to
The Stormont government has been suspended since 2002
Meanwhile, a former IRA prisoner has challenged the DUP MP, Jeffrey Donaldson, over his attitude to decommissioning.
Seanna Walsh, who was arrested in 1988 in connection with a home made bomb, questioned the Lagan Valley MP during an event at the West Belfast Festival on Wednesday.
He said decommissioning was a "red herring" because people could always get more weapons if they wanted to.
However, Mr Donaldson insisted decommissioning was an essential element of the peace process.
"Whether people like it or not, the unionist community does not trust the IRA because of what has been visited upon them by the IRA over 30 years.
"We need to see the weaponry being dealt with in a credible verifiable way, within a defined timescale.
"I would prefer it to be dealt with as soon as possible, preferably before the end of 2004."
Last month, Mr Donaldson said unionists would guarantee the stability of political institutions in Northern Ireland if republicans abandoned paramilitarism for good.
Intensive negotiations are set to take place in September in an attempt to get devolution restored in Northern Ireland.