The spokesman told AFP the Irish government was aware of plans to ship weapons-grade plutonium from the United States to France for re-processing but it was receiving insufficient information about shipments.
The French Areva energy group said on Friday that two British nuclear transport ships, the Pacific Teal and the Pacific Pintail, were leaving Barrow-in-Furness in Britain for Charleston in the United States.
"Their journey is part of a program being implemented by the United States Department of Energy (USDOE) for the disposition of former weapons plutonium by using it in a nuclear reactor for generating electricity.
"The program starts with the manufacturing of four nuclear fuel assemblies in France," Areva said.
In Charleston, the plutonium will be loaded onto the ships in casks specially designed for the safe and secure transport of plutonium oxide.
"The ships will then leave for France, where the plutonium will be turned into nuclear fuel at the COGEMA sites of Cadarache and Marcoule."
The cargo will be protected by armed guards and the two ships are equipped with naval guns.
The ministry spokesman said Ireland want a formalised arrangement where "shipping states would inform coastal states" about the transport of hazardous cargoes.
"We are at the gateway to the Atlantic and we would obviously monitor such shipments very closely. We want a situation where, if there is any shipment of nuclear or other hazardous waste, we should receive full information about it.
"At the moment we would not necessarily be party to all the information about a shipment between private companies and we are dissatisfied about that," the spokesman said.
Ireland is backing a resolution to be presented at a meeting of the International Energy Agency in Vienna later this month.
The spokesman said that, if passed, the resolution would require nuclear states and nuclear companies to provide much more detail to coastal states about nuclear shipments.
Environment group Greenpeace claimed the plutonium was to be trucked over 1,000 kilometres in France in highly vulnerable trucks to plutonium fuel-manufacturing facilities before being returned to the United States next year.