Former United States Secretary of State George Shultz, now a strong anti-nuclear campaigner, does not believe that US Navy ships could resume visiting unless New Zealand accepts Washington's "neither confirm nor deny" policy about a vessel's nuclear capability.
"It's impossible as long as New Zealand doesn't accept the no-confirm-or-deny policy,"
Mr Shultz said yesterday.
Prime Minister John Key said in Washington that such a visit would be only symbolic anyway and it was "not of any great consequence".
Mr Key did not believe US warships would return to New Zealand ports "any time real soon".
Mr Shultz was Secretary of State from 1982 to 1989 under President Ronald Reagan, including in 1984 when the rift in the Anzus defence alliance occurred over New Zealand's opposition to nuclear warships.
Former Prime Minister Sir Geoffrey Palmer was Acting Prime Minister when New Zealand turned down Mr Shultz's request to send the SS Buchanan and has reignited discussion about how far the thaw should go.
He said at the weekend it would be "desirable" for the ship visits to resume.
Speaking from California to the Herald, Mr Shultz, now aged 89, said he remained "a big fan of New Zealand's".
"New Zealand was always a wonderful country to work with. We had a little disagreement about nuclear things which strained the Anzus alliance but I remember saying at the time, 'We part, but we part as friends.'"
Mr Shultz praised President Barack Obama for holding the nuclear security summit in Washington aimed at reducing the risk of nuclear terrorism.
Mr Shultz and other elder statesmen, including former Secretary of State Henry Kissinger and former Secretary of Defence William Perry, have been commended by Mr Obama for the leadership they have shown in advocating the elimination of nuclear weapons.
They have made a film, The Nuclear Tipping Point, which had a special White House screening last week.
Secretary of State Hillary Clinton has been talking up the strength of the US nuclear arsenal but Mr Shultz does not believe that sends a mixed message.
"I think it is important that the United States maintains a safe, secure and reliable stockpile of nuclear weapons as long as nuclear weapons exist," he said.
"They have a deterrent value of course, a very big deterrent value. That's why you keep them."
