Japan’s Prime Minister Shinzo Abe is in The Hague after agreeing on a landmark deal to hand over weapons-grade plutonium and enriched uranium stocks to the U.S.

The two-day Nuclear Security Summit wraps up today in the Netherlands.

American and Japanese officials yesterday (Monday) announced an accord on minimizing nuclear substances and strengthening security oversight of nuclear materials.

Japan pledged to transfer hundreds of kilograms of plutonium and highly enriched uranium from the Japan Atomic Energy Agency for disposal in the U.S.

The substances were originally purchased by Japan for research and could be used as part of the nuclear cycle.

Abe’s administration announced the deal in time for the summit without waiting for his ruling coalition to finalize the country’s basic energy plan.