The campaigning family of murdered Belfast man Robert McCartney is having a private meeting with US President George W Bush at the White House.
Robert McCartney's sisters and partner are meeting Mr Bush
They are expected to give Mr Bush a dossier which details their claims that IRA members were behind the murder of the father-of-two on 30 January.
It comes a day after their campaign for justice received backing from some of America's most influential politicians.
Catherine McCartney said they were confident of the president's support.
"We are certainly aware that from the response of the American people that they see this as a simple issue of justice," she said.
"The American people have supported the peace process for over 10 years."
Mr McCartney, 33, was stabbed to death following a row in a Belfast bar. His family has blamed the IRA for the murder and subsequent interference with evidence and witnesses.
On Thursday, Irish Prime Minister Bertie Ahern presented President Bush with a bowl of shamrock at the White House reception.
He said the Irish government was as fully committed as in 1998 to making the Good Friday Agreement work and knew they could count on President Bush's continued support.
He said inclusive government in Northern Ireland was only possible when there was "definitive closure to paramilitary capability and activity including all forms of criminality".
Unlike previous years, Northern Ireland's politicians were not invited to the annual celebrations.
Sinn Fein President Gerry Adams, who was denied a meeting with Mr Bush, held talks with Mr Ahern in Washington on Wednesday.
Speaking afterwards, Mr Adams described the meeting as "useful" and said it gave them the opportunity to focus collectively on how outstanding issues could be resolved.
President Bush invited the McCartney family to the White House as part of a gesture to all those working towards peace in Northern Ireland.
Mr Bush said he was looking forward to meeting Mr McCartney's five sisters and his fiancee, Bridgeen Hagans, who he referred to as "these very brave souls".
On Wednesday, the US Special Envoy to Northern Ireland, Mitchell Reiss, met the McCartney family and said the US administration was doing all in its power to help them.
The family also held talks with US Senator Ted Kennedy, who has refused to meet Gerry Adams during the Sinn Fein leader's St Patrick's week trip to the US.
A spokeswoman for Senator Kennedy said he had cancelled a meeting because of the IRA's "ongoing criminal activity".
NI politicians are off the White House guest list
Senator Kennedy said the family's presence in Washington "sends a very powerful signal that it's time for the IRA to fully decommission, end all criminal activity and cease to exist as a paramilitary organisation".
The McCartney family's visit to America comes after Sinn Fein criticised the handling of the murder inquiry by police in Northern Ireland.
Martin McGuinness accused the police of "unprecedented and incredible delays" in questioning key suspects and witnesses just to damage his party.
Three men were expelled by the IRA after the killing, including the two main suspects in the case.
PSNI Chief Constable Hugh Orde, who has travelled to Washington, said the police would decide when the time was right to make arrests.
"I think the public understand the difference between intelligence and evidence - they are ahead of us on this," he told BBC Radio Ulster.
"They know very well that we need a case to put to people."