New Zealand can be assured the American warship being sent to our navy's 75th anniversary celebrations will not be nuclear propelled or nuclear armed.

That's according to one academic, following an invitation extended to the US Navy for next November's event.

Professor of Strategic Studies at Victoria University, Robert Ayson, says the Americans sending a warship won't pose any problems for New Zealand.

"You can be truly sure and very sure, in fact, that a vessel of the nature that will come will not be nuclear armed or nuclear propelled."