He stated: “I, Bill de Blasio, Mayor of the City of New York, do hereby proclaim March 17 2018 in the city of New York as ‘Gerry Adams Day’.
This has naturally infuriated Unionists. “The proclamation was a kick in the teeth for the victims of terrorism and brings shame on the office which he holds," said Ulster Unionist Party MLA Steve Aiken.
He added: "His eulogy of Adams then rubbed their noses in the dirt and has caused further pain and hurt.
"The truth played little role in his oration and is instead an attempt to rewrite history. The fact that he tried to tie St Patrick`s Day into it is an insult to the law abiding majority on these islands who celebrate the day.
“It is hard to believe that the Mayor of New York City, a city which has suffered so grievously at the hands of terrorists could grovel at the feet of a man who continues to be an apologist for the terrorist death squads of the Provisional IRA."
Labour Party Leader, Brendan Howlin, has said it was both "unfortunate and inappropriate".
Mr Howlin also said it was even more inappropriate that the Mayor should maker such a proclamation in the presence of the Taoiseach, the democratically elected leader of the Irish nation.
Deputy Howlin commented: "Mr Adams was directly involved in an organisation responsible for almost 1,700 deaths during the troubles.
"We are all pleased that that killing was brought to an end and while Mr Adams is entitled to his share of the credit for that it, it does not wipe out his culpability for the IRA's murderous campaign. Nor is the mayor of New York or anybody else entitled to rewrite our history.
“If we are to have a serious conversation about a united Ireland with unionism it will be all the stronger if we have ceased glorifying this murderous campaign and those that conducted it."
He added: “The Taoiseach has questions to answer too. Did he know that Mr Adams was to be presented this award?
"He certainly should have been informed by the Mayor's office that he was intent on making this announcement. If not it is a breach of protocol. If Mr Varadkar remained knowing what was taking place it is the latest in a series of errors of judgement."