The two-day Nuclear Security Summit in Washington ended on Tuesday, with leaders from 47 nations signing a document calling for joint efforts to ensure nuclear security.

The first multilateral summit in the 21st century on global nuclear security consolidated consensus among world members to keep terrorists, criminals and other unauthorized actors from acquiring nuclear material, including highly enriched uranium and plutonium.

In the 12-point document, 47 participating countries pledged "sustained and effective international cooperation" to secure all vulnerable nuclear material in four years. Global nuclear security requires the peaceful and secure use of nuclear power, and for nuclear weapons to be possessed by countries only with reason. Despite increasing energy options, any improper use of nuclear technology is likely to cause enormous harm to the global community.