There is "no hope" of political progress until the issue of IRA criminality has been dealt with, the Northern Ireland secretary has said.
The IRA has been accused of ongoing criminal activity
Paul Murphy told the BBC the onus was on Sinn Fein to act.
Mr Murphy also praised the courage of the McCartney sisters who have taken their campaign for justice over the murder of their brother to the US.
Robert McCartney died in a bar row. His family blames the IRA for the murder and intimidating witnesses.
Mr Murphy was speaking to BBC Radio 4's Today programme from Washington, where he had attended the St Patrick's week festivities.
Mr Murphy said: "As far as the political process is concerned, to all intents and purposes we are not talking about any future negotiations or discussions until the issue about criminal activity on the part of the IRA is addressed."
He said until that happens there "wasn't any hope at all" of progress to restore the institutions of government in Northern Ireland.
The secretary of state also highlighted the way in which the McCartneys' campaigning had changed the political landscape of the peace process.
Robert McCartney, 33, was killed near Belfast city centre
He said the "the whole of this week has been about criminal activity on the part of the IRA in some form or another."
He said the McCartney sisters' "remarkable campaign" had "personalised the issue of criminal activity" because people were able to see individuals who had suffered from brutality and savagery.
He said their campaign had been very well understood in the US.
The McCartneys met US President George W Bush at the White House on Thursday, and said they had been "encouraged" by his response.
Mr McCartney's sisters and partner gave Mr Bush a dossier which details their claims that IRA members murdered the father-of-two on 30 January.
Meanwhile, SDLP leader Mark Durkan has said the unwavering stand of the five sisters had moved the peace process at unprecedented speed.
"The McCartney family is very clear about what justice demands and has held strong to those demands where the two governments have faltered," he said.
"By doing that they have moved the movement on five times in as many days."
On Thursday evening, Sinn Fein leader Gerry Adams said the case had become steeped in politics.
Mr Adams, who is on his way to Cleveland to meet supporters, said the only people who could not be accused of political motivation were the McCartney family themselves.