Howe is one of countless conservationists lauding the decision.
The Kermadec region serves as a breeding and feeding ground for a diverse range of marine mammals, fish and invertebrates. Among them are dolphins, whales, sharks, tuna, sunfish, turtles, coral and other threatened or endangered marine species that suffer from the effects of destructive economic marine activities like fishing and drilling.
Geologically, the region is the host of the world's longest chain of submerged volcanoes and the second deepest ocean trench.
The WWF has campaigned for the sanctuary for more than eight years with the Pew Charitable Trust and Forest & Bird.
"This ocean sanctuary is a major conservation victory and is testament to many years of hard work by thousands of New Zealanders," says Howe.
"Together we've helped establish a large haven in the Pacific that will allow some of the ocean's most exploited and threatened species to not only recover but flourish."