The U.S. Department of Defense disclosed on Monday that it has 5,113 nuclear warheads in its arsenal, and several thousand more are waiting to be dismantled.

The unprecedented announcement marks only the second time in history that the United States has released the top secret information, and comes in the midst of a high-level United Nations conference taking place to review international nuclear treaties.

"We think it is in our national security interest to be as transparent as we can be about the nuclear program of the US," Secretary of State Hillary Clinton told reporters at the nuclear Non-Proliferation Treat (NPT) conference.

The World Council of Churches (WCC), which sent a delegation to the NPT conference, called the announcement an answer to a "call heard since the days of the Cold War from any quarters, including the WCC."

The WCC delegation also noted other positive signs at the NPT review including a majority of participating governments expressing favor towards starting work on a nuclear weapons convention, which would ban the use of nuclear weapons in their entirety.

Governments have also stressed an urgent need for a nuclear-weapon-free zone in the Middle East.

Members of the WCC delegation include the Rev. Dr Michael Kinnamon, general secretary of the National Council of Churches of Christ in the USA; the Rev. Dr Gunnar Stalsett, moderator of Religions for Peace and former bishop of Oslo; and Dr Ninan Koshy, a current events commentator and international affairs analyst.