SIS and GCSB Minister Chris Finlayson said he had met with Comey on a number of occasions, and said "he struck me as a very nice man".
He would not comment on his sacking, saying he "did not get into those things because it's a sovereign country and it would be inappropriate".
Trump's decision to abruptly fire Comey ignited a political firestorm in the United States.
"Today, President Donald J. Trump informed Comey that he has been terminated and removed from office," the White House revealed in a statement, which said Trump had acted on the advice of his Attorney General, Jeff Sessions.
James Comey arrives in Queenstown for a meeting in April. Photo / Brett Phibbs
"The FBI is one of our nation's most cherished and respected institutions and today will mark a new beginning for our crown jewel of law enforcement.
"A search for a new permanent FBI Director will begin immediately."
The White House statement did not elaborate on the reason for Comey's dismissal, though Sessions' recommendation to the President stated the government needed to "reaffirm its commitment" to "the integrity and fairness of federal investigations and prosecutions".