Japan to turn over nuclear material to US

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 US.

The plan is part of US 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 hold excess stockpiles. The amount to be returned to the US 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.