"We have supplementary events, if you like, that record participation in Europe, North Africa, places like that -- and of course the relationship in the Pacific," he said.
"Those are all important parts and we should mark all of them. We shouldn't see all of them needing to be incorporated in the Anzac Day process."
McCully and Talagi unveiled a plaque from the New Zealand Government at Tomb Point at the waterfront in the capital Aliofi.
Three Niueans who died in the war, Privates Alotau, Mitipauni and Muimatagi, were also added to the New Zealand Roll of Honour.
Hundreds of local and New Zealand Niueans attended a church service at the Aliofi Church where the Niuean soldiers had their final service before the left for the war.
During the service, excerpts were read from the diaries of the men, describing the Western illnesses they suffered and the pain of hearing other Niuean soldiers had died.
In one excerpt, a soldier said he met a British prince and told him he came from Niue. He said he was shocked the prince did not know where Niue was.
Reverend Vilikamupala Viviani delivered a sermon, comparing the Niueans during the war to the "peacemakers" who received the blessings of God in the Bible.
Eighty-seven-year-old West Auckland woman Vai Apelu returned to Niue with her daughter to honour the service of her father Taulata.
"It is a great thing for our family, we are so proud of our grandparents and it is very special to be able to be there and remember what they did," she said.