United Nations Security Council summit on Nuclear Non-proliferation and Disarmament.

Stopping the spread of nuclear weapons and preventing nuclear terrorism is a shared responsibility, said Under Secretary of State for Arms Control and International Security Ellen Tauscher.

In prepared remarks for the United Nations General Assembly First Committee, Under Secretary Tauscher said the administration of President Barack Obama is taking "concrete steps" toward a nuclear weapons free world, noting the effort must be "a shared responsibility because no single nation, no matter how powerful, can do this alone."

The United Nations Security Council Resolution 1887, adopted unanimously on September 24, 2009, was an important step, said Under Secretary Tauscher, in reducing the threat from nuclear weapons. She noted that the measure calls on all parties to the Nuclear Non-Proliferation Treaty, the NPT, to comply fully with their nonproliferation and disarmament obligations, "affirms that effective [International Atomic Energy Agency] safeguards are essential to nonproliferation," and "makes clear the Security Council's intent to address NPT violations."

Under Secretary Tauscher said the effort to reinvigorate the NPT calls for a global response. The United States is negotiating a follow-on agreement to the Strategic Arms Reduction Treaty with Russia to further reduce the number of nuclear weapons and delivery systems.

President Barack Obama has called for an April 2010 summit on nuclear security to address the threat from nuclear terrorism and the need to secure nuclear materials.

The Obama Administration also will pursue ratification of the Comprehensive Nuclear Test Ban Treaty, or CTBT. Secretary of State Hillary Clinton led the U.S. delegation to the CTBT Article XIV Conference on Facilitating the Treaty's Entry into Force on September 24, 2009, after a 10-year U.S. absence from that forum.

To end the production of materials needed for nuclear weapons, the U.S. supports the negotiation of a Fissile Material Cutoff Treaty, as part of a program of work adopted in May 2009 by the Conference on Disarmament in Geneva.

Responsibility for reducing the threat from nuclear weapons, said Under Secretary Tauscher "does not end with a decision to forgo nuclear weapons and accept safeguards to demonstrate the sincerity of that decision. It must continue through the participation in collective efforts to impede others from crossing the nuclear threshold."