A plan to ship mixed-oxide fuel from Europe for the first time has been submitted to the United States, government officials said Friday.

The action kicked off official discussions between Japan and the U.S. under the Agreement of Cooperation, which concerns peaceful uses of nuclear energy, they said.

Under the plan, containers of mixed plutonium-uranium oxide fuel will be transported to Japan from Britain and France aboard two British-flagged freighters. The freighters assigned to carry the fuel will not be escorted by any naval or coast guard vessel. Instead, they will be refitted and armed to escort each other.