Speaking at Auckland's Mt Smart stadium for Pasifika Festival, the Prime Minister said the Government would be guided by the Queen's wishes in planning the New Zealand memorial for Prince Philip.
Ardern said she received the news overnight.
"It is with great sadness that we receive that news. The Duke had a strong connection to New Zealand," Ardern said.
"He visited with her Majesty the Queen on 10 occasions and then had additional solo visits. The first was in 1953 and the last was in 2002. He had a connection to a number of New Zealand organisations both as patron and supporter, including for instance the New Zealand Defence Force."
Ardern cited the Duke of Edinburgh awards in particular that for more than 50 years have tied Prince Philip to thousands of New Zealand youth.
"It is fair to say, it will be a hugely significant loss for New Zealand, and those organisations that were supported by Prince Philip," she said.
"Perhaps most importantly he has served in support of Her Majesty the Queen for many many years in her service to New Zealand, the commonwealth and indeed the world."
Ardern confirmed a memorial would be held in New Zealand after his formal funeral in the UK.
"Her Majesty, I understand, is currently considering those arrangements which they have suggested will be modified based on the current Covid status in the United Kingdom."
Ardern said she had not had conversations with the royal family since Prince Philip's death and she "wouldn't expect to".
"I will be making sure on behalf of the people of New Zealand that we do pass our condolences on in a formal way, most likely in writing to the royal family but especially to Her Majesty The Queen," she said.
Flags will be flown at half mast in New Zealand in recognition of Prince Philip's death, and an online register for citizens to express their condolences has also been established.
Ardern said because Prince Philip stepped away from the public facing aspects of his royal duties in 2017, just as she became Prime Minister, most of her royal interactions had been with the Queen.
"But of course like every New Zealander I have memories of his presence in his role alongside her as she performed public duties on behalf of New Zealand, and of course he had a number of solo visits here. So those are my memories of him," Ardern said.
In a written statement last night Ardern, also expressed her "sincere condolences" to the Queen and royal family.
"Our thoughts are with Her Majesty The Queen at this profoundly sad time. On behalf of the New Zealand people and the Government, I would like to express my sincere condolences to Her Majesty and to all the Royal Family.
"Prince Philip will be fondly remembered for the encouragement he gave to so many young New Zealanders through The Duke of Edinburgh's Hillary Award. In over 50 years of The Award in New Zealand, thousands of young people have completed life-changing challenges through the programme".
Kiwis would also remember the Duke of Edinburgh's "enormous support" for the Queen.
"His time as royal consort exceeded that of any other royal consort in British history. His Royal Highness accompanied The Queen on her ten visits to New Zealand, the first being in 1953, and the last in 2002."
Ardern had directed that flags on all government buildings and naval vessels be flown at half-mast.
The Government was awaiting details from the palace concerning the arrangements for the Duke of Edinburgh's funeral, she said.
"Following the funeral, a national memorial service will be held in Wellington. More details will follow once arrangements have been confirmed."
New Zealand Governor-General Dame Patsy Reddy said the Prince's death was a "great loss to Her Majesty the Queen, the members of the Royal Family and the people of Her Majesty's Realms and territories".
"On behalf of the people of New Zealand, I convey our deepest condolences on the death of His Royal Highness Prince Philip. Our thoughts are with the members of the Royal Family at this time of great sorrow.
"New Zealand shares with the people of Her Majesty's Realms a tremendous sense of sadness at the great personal loss you have suffered," she said.
"We have fond memories of His Royal Highness's visits to New Zealand, and will remember his commitment to Commonwealth nations and his dedication to raise awareness of threats to the world's wildlife."
National Party leader Judith Collins paid tribute the Prince Philip's "truly impressive" charity work.
"His legacy will live on for many more decades to come."
