Sinn Féin has been banned from fundraising in the United States, the Timesof London has reported, citing diplomatic sources.
It said the order, passed to Sinn Féin leader Gerry Adams via the US State Department, followed White House anger over accusations the IRA was continuing criminal activity.
The paper did not say how long the ban would last.
Mr Adams is on a week-long tour of the United States and has come under fire for his party's ties to the IRA following the Northern Bank robbery and the murder of Robert McCartney.
For the first time in a decade, the North's political leaders have not been invited to the White House for the annual St Patrick's Day celebrations.
The Timesalso reported that London had raised the threat level for IRA activity in Britain for the first time since the Belfast Agreement was adopted in 1998.
A Home Office spokeswoman declined to comment.