President Michael D Higgins said Thatcher’s key role in signing the agreement was a valuable contribution to the search for peace.
Mr Kenny said he was saddened to have learned of her death and extended his deepest sympathies to her family.
“While her period of office came at a challenging time for British-Irish relations, when the violent conflict in Northern Ireland was at its peak, Mrs Thatcher signed the Anglo-Irish Agreement which laid the foundation for improved North-South co-operation and, ultimately, the Good Friday Agreement.”
President Higgins said Tha-tcher would be remembered as one of the most conviction-driven prime ministers.
“The policies of Mrs Thatcher’s government in regard to Northern Ireland gave rise to considerable debate at the time. However, her key role in signing the Anglo-Irish Agreement will be recalled as a valuable early contribution to the search for peace and political stab-ility.”
Tánaiste Eamon Gilmore said: “Baroness Thatcher was a hugely influential figure in British and global politics. Always controversial, her legacy is now for the historians.”
Fianna Fáil leader Micheál Martin said there would be much discussion on her legacy in the coming days.
“However, the British prime minister’s hardline approach to an increasingly violent situation in the North was one of a number of factors which limited the potential of those early initiatives.
“Unfortunately her uncompromising approach to the escalating crisis in the early 1980s may actually have acted as a major boost for the recruitment efforts of the Provisional IRA at that time.
“While I or the Fianna Fáil party would have had little in common with the politics of Mrs Thatcher, it would be wrong not to acknowledge that the long journey towards the peace and respect that we enjoy between Britain and Ireland today, took its first faltering steps in the bilateral discussions between Mrs Thatcher and former Taoiseach Charles Haughey.”
Gerard Collins, a former justice and foreign affairs minister, said Thatcher had been a formidable politician.
“She was, during her day, an exceptionally important person, not just in the British government sense but also in the European and international sense.
“She was a major figure and an exceptionally able person. She was very, very clear in her focus in her objective and I’m talking now about European and not just Ireland.
“And she was exceptionally determined in achieving her objectives.”