Ministers from the Northern Ireland Executive and the Irish Government condemned those who murdered prison officer David Black at a recent North South Ministerial Council (NSMC) meeting, on 6 November 2012.
Mr Black, 52, from Cookstown, was shot dead on the M1 in County Armagh on Thursday as he drove to work at Maghaberry Prison.
In his statement to the Assembly, Deputy First Minister Martin McGuinness said Mr Black's murder was discussed at the meeting.
"Minister's reaffirmed their determination that actions such as this will not be allowed to drag us back to the past," he said.
"The people who murdered David Black do not speak for the people of Ireland."
Chris Lyttle of the Alliance Party said he welcomed "the united condemnation from throughout Ireland".
Mr McGuinness also addressed other matters, and said construction of the radiotherapy unit at Altnagelvin hospital, in Londonderry, was to begin in 2013 and would be completed in 2016.
The minister added that ministers had discussed maximising the economic benefits of the World Police and Fire Games, the UK City of Culture celebrations and The Gathering.
In response to a question from the DUP's Stephen Moutray about the benefits of Ireland's forthcoming Presidency of the EU, Mr McGuinness said that the NSMC had a role to play to ensure that both the Irish Republic and Northern Ireland benefited.