EFFORTS to deal with Northern Ireland's troubled past have failed, Amnesty International claimed.
The human rights organisation urged speedy action to investigate allegations of abuse.
Former US diplomat Dr Richard Haass chaired five-party political talks on dealing with more than 3,000 unresolved conflict deaths and associated victims' issues which ended without agreement at the end of the year.
He will join Amnesty to brief an influential US congressional committee in Washington tomorrow.
Patrick Corrigan, Amnesty's Northern Ireland programme director, said: "The longer politicians take to deliver new mechanisms to deal with the past, the longer victims and bereaved family members are being left to suffer a denial of the right to truth and justice."
Mr Corrigan added: Following the failure of the parties to reach agreement it is imperative that US political pressure is brought to bear, not just on Northern Ireland leaders but also the UK and Irish government who have specific responsibilities to discharge with respect to the past."
The Haass proposals envisaged a Historical Investigations Unit to take on the investigatory responsibilities of the police's Historical Enquiries Team and the Police Ombudsman's office.
They included the creation of an Independent Commission for Information Retrieval (ICIR) probing what happened to victims' loved ones.
The ICIR would also have responsibility for assessing wider themes and patterns in the conflict – including alleged State security force collusion with paramilitaries or claimed IRA ethnic cleansing campaigns.
Unionists are unhappy at the number of potential themes suggested by Dr Haass that focus on alleged illegal activity by State forces.