The former diplomat, academic and author Denis McLean has died suddenly in Wellington at the age of 80.
Mr McLean died from a heart attack at his home on Wednesday.
He was Secretary of Defence for 10 years from 1979 and ambassador to the United States from 1991 to 1994, during the time when friction from New Zealand's anti-nuclear stance was at its greatest.
He held professorships in several international studies centres and was the author of a biography of Sir Howard Kippenberger and other books on international relations and walking.
The chief executive of Te Araroa Trust, Geoff Chapple, says Mr McLean had relentless energy and an enormous social network, and his book Te Araroa was the inspiration for the name of a walking trail the length of New Zealand.
Mr McLean is survived by his wife, Anne, and three children.