The US Senator Ted Kennedy has called off talks with Sinn Féin leader, Gerry Adams, which had been scheduled for next Thursday.
A spokeswoman for Mr Kennedy said the senator had decided not to meet Mr Adams because of what she said was the IRA's ongoing criminal activity and contempt for the rule of law.
The spokeswoman said the murder of Robert McCartney underscores the need for IRA violence and criminality to stop and for Sinn Féin to co-operate with the PSNI.
Mr Adams has already been refused a meeting with President Bush at the White House and will not be attending the St Patrick's Day lunch hosted by the Speaker of the House of Representatives, Dennis Hastert.
