President Michael D Higgins has said he hopes the British government can find a way of responding to a "reasonable and constructive" request that documents on the Dublin and Monaghan bombings be given to an independent judicial figure.
He said there was a collective responsibility to find a way to deal with the legacy of the Troubles and he said amnesia was not an option.
Speaking at Áras an Uachtaráin, he said a positive and resounding change had occurred in the relationship between Britain and Ireland.
Two governments must be willing to encourage each other to do more in addressing the needs of victims and survivors, he said.
Forty years ago, the Dublin and Monaghan bombings killed 33 people, plus an unborn baby, and injured hundreds.
The families of the victims believe British state forces colluded with loyalist paramilitaries in the attacks.
President Higgins said that while the inquiry by Judge Henry Barron had uncovered some answers about what happened, many questions remain unanswered.
He was hosting the Justice for the Forgotten victims' group at a special event marking the 40th anniversary of the attacks.