Sinn Fein leader Gerry Adams has said Margaret Thatcher caused "great hurt to the Irish and British people" during her time as Prime Minister.
"Working class communities were devastated in Britain because of her policies.," he said.
"Margaret Thatcher will be especially remembered for her shameful role during the epic hunger strikes of 1980 and 81.
"Her Irish policy failed miserably."
Northern Ireland First Minister Peter Robinson paid tribute, describing Baroness Thatcher as "undoubtedly one of the greatest political figures of post-war Britain and she changed the face of our United Kingdom forever.
"Whilst we disagreed over the Anglo-Irish Agreement, Mrs Thatcher was committed to the union and later described the Anglo-Irish Agreement as one of her greatest regrets."