British and Irish relations have never been stronger, but the governments still disagree on the calls for an inquiry into the murder of solicitor Pat Finucane, Taoiseach Enda Kenny has said.
The Irish prime minister gave the Chancellor's Lecture at the University of Ulster in Belfast.
And Mr Kenny stressed the huge progress in the peace process and in building new relationships across the Irish Sea.
But he used the speech to repeat his support for Mr Finucane's widow who has rejected Prime Minister David Cameron's decision to order a review of the case rather than the promised public inquiry.
Mr Finucane was shot by loyalist paramilitaries at his north Belfast home in 1989, but the government has apologised after security forces were exposed as having colluded in the killing.
Mr Kenny said: "Prime Minister David Cameron and I signed a joint statement on intensifying British-Irish relations for the next decade. This important initiative recognises that British Irish relations have never been stronger.
"The state visit of Her Majesty The Queen last year served as a symbol of a modern, deep and friendly relationship. Gone are the days of cold, insular suspicion and conflict."
He praised progress in the peace process, but condemned the continuing violence of dissident republicans. But he added: "While working closely with my British counterpart, there are matters on which we share a difference of opinion.
"Late last year, I had the privilege of presenting Geraldine Finucane with a Person of the Year Award in Belfast and I want to say once again how much I respect and admire the way she has campaigned for over 22 years, with great dignity and courage, and I support her in her campaign for a full public inquiry."
Celebrating the efforts to tap in to Northern Ireland's tourism potential, and hailing the potential of cross-border economic cooperation, the Taoiseach said: "There are many positive signs for the future in Northern Ireland."