US and Japanese officials say Japan to turn over nuclear weapons material to United States

American and Japanese officials say Japan plans to turn over more than 700 pounds of weapons-grade plutonium and a supply of highly enriched uranium to the U.S.

The plan is part of U.S. President Barack Obama's years-long effort to secure nuclear material around the world.

Japan possesses large amounts of plutonium, despite its pledge to not to hold excess stockpiles. The amount to be returned to the U.S. this time is a fraction of Japan's overall stockpile.

The plan is to be formally announced Monday at a Nuclear Security Summit in the Netherlands. The officials insisted on anonymity to confirm the plan ahead of that announcement.