The British Government should urgently introduce measures addressing the legacy of Northern Ireland's violent past, Amnesty International said.
Northern Ireland Secretary Karen Bradley is to consult on mechanisms for investigating historic wrongdoing envisaged in the Stormont House Agreement between the main parties following the collapse of powersharing talks.
Amnesty said Northern Ireland had failed "dismally" to deal with past human rights violations, end "discrimination" on marriage equality and reform "outdated" abortion laws.
Northern Ireland campaigns manager Grainne Teggart said: "The collapse of the Stormont talks is no justification for the continuing denial of rights.
"The Secretary of State Karen Bradley must deliver on legacy issues, marriage equality and abortion reform."
She said conflict victims continue to suffer the consequences of political failure to properly address past human rights abuses.
"We welcome the Secretary of State's comments that she will consult on implementation of bodies set out in the Stormont House Agreement and support reform of inquests.
"This must be done urgently and bring an end to the denial of truth and justice."
A number of new agencies were agreed by political leaders under the 2014 Stormont House Agreement.
An Historical Investigations Unit would examine unsolved murders while an Independent Commission on Information Retrieval would help families to learn more about the fate of their loved ones.
Northern Ireland remains the only part of the UK where same-sex couples cannot marry.
Ms Bradley has said it is a devolved matter but the power of Westminster to legislate remains unaffected.
She has added: "If this issue were to be raised in Westminster, the Government's policy is to allow a free vote on matters of conscience such as equal marriage."
The DUP has argued in the past that people in same-sex relationships are free to enter civil partnerships but marriage is between a man and a woman.
Ms Teggart said the UK Government must end "daily discrimination" against same-sex couples and introduce legislation at the earliest opportunity bringing Northern Ireland's laws on marriage equality into line with the rest of the UK.
She added: "The rights of LGBT+ people in Northern Ireland to be treated equally should not be held to ransom by the absence of devolved government and a seemingly never-ending talks process that has so far failed to progress these issues. The UK Government can and must fix this."