It’s a pleasure to join my colleagues on this important and timely subject.

Just last month, I was in Kazakhstan to commemorate the 25^th anniversary of the closing of the nuclear test site at Semipalatinsk that was witness to nearly 500 nuclear tests that shook the earth and clouded the skies with radioactive dust.

And one year ago, I was honored to meet Yoshitoshi Fukahori who, as a teenager, survived the bombing of his hometown of Nagasaki. Mr. Fukahori gave me a tour of his photo exhibit depicting the aftermath of that August morning 71 years ago. He shared his images and his own personal tragedy in the hopes of sparing future generations the same fate.

It is our deep understanding of the destructive force of nuclear weapons that led the United States, in the years since, to work together with the Soviet Union to reduce nuclear weapons inventories and to draw the nuclear arms race between our nations to a close. It also informs President Obama’s vision, as articulated in Prague in 2009, to pursue a world without nuclear weapons and to extend forever the seven-decades-long record of their non-use.

The President also acknowledged in that same speech that the fulfillment of this agenda would not occur overnight, and might not even happen in his lifetime, but we could set the course and push ahead.

As a first step, the 2010 U.S. Nuclear Posture Review (NPR) outlined five key objectives to advance the President’s vision: reducing the role of nuclear weapons in U.S. national security strategy; preventing nuclear proliferation and nuclear terrorism; maintaining strategic deterrence and stability at reduced nuclear force levels; strengthening regional deterrence and reassuring U.S. allies and partners; and, sustaining a safe, secure, and effective nuclear arsenal.

A few months later, the United States and Russia signed the New START Treaty, which both sides continue to implement and are on their way toward meeting the central limits in February 2018—capping the strategic forces of the United States and Russia at their lowest level since Dwight Eisenhower occupied the White House.

In 2013, in Berlin, the United States declared its willingness to pursue further reductions in deployed strategic nuclear weapons up to one-third below the New START levels. This offer remains on the table.

Even as we work to make further progress, it is worth noting that the United States has reduced its total stockpile of active and inactive nuclear warheads from a height of 31,255 nuclear weapons in 1967 to 4,571 as of 2015, while seeking to maintain the strategic stability that provides a foundation for global security.

The strategic course we have taken, and the one we will continue to pursue, is based on the principles of consensus, and most importantly verifiability. It reflects the reality that we cannot separate disarmament from the global security environment or strategic stability considerations. Most importantly, there is demonstrable, continual proof that our strategy works.

The latest proof of this fact was the adoption of UN Security Council Resolution 2310 just last Friday. This resolution reaffirms that national moratoria against nuclear explosive testing are an example of responsible international behavior and encourages countries to make the necessary preparations for the day when the Comprehensive Nuclear-Test-Ban Treaty (CTBT) enters into force.

Only through U.S. ratification of the CTBT, a key step towards the Treaty’s entry-into-force, can we make permanent the benefits of the Treaty. North Korea’s latest nuclear test, in flagrant violation of its international obligations, demonstrated the strength of one of those benefits—the Treaty’s robust verification architecture. The International Monitoring System (IMS) and the International Data Centre (IDC), at the heart of the Treaty’s verification regime, performed admirably. Within minutes, more than 30 IMS stations detected a seismic event, consistent with the foot-print of past North Korean nuclear tests.

The rapid detection of this event, and the previous 4 North Korean nuclear tests, highlights the effectiveness of CTBTO’s verification regime, and why the United States is engaged in an effort to educate the public and Congress on one of the national security benefits gained through the Treaty’s entry-into-force.

In contrast to the U.S. approach to build upon decades of pragmatic steps to reduce the role and number of its nuclear weapons, a group of nations seeks to derail our current course in favor of a nuclear weapons ban.

Pursuit of such a ban is unrealistic and impractical. Unrealistic in that it fails to factor in the international security environment, and impractical since such a treaty would presently be unverifiable. That’s not a good start for any initiative relating to nuclear weapons.

The unfortunate irony of the current ban treaty movement is that it could actually end up harming the proven, practical, and inclusive efforts that have achieved tangible results on disarmament, and will continue to do so.

Nuclear disarmament can only be achieved through an approach that takes into account the views and the security interests of all states – every state. That is why the United States rejects the final report from the Open Ended Working Group on nuclear disarmament (OEWG) and will oppose any resolution at the United Nations this year commencing negotiations on a legally binding instrument banning nuclear weapons.

Despite the rhetoric about the size of the group pushing for a ban treaty, the majority of the world’s population – over four billion people – lives in a nuclear weapon state or one that is covered by a nuclear deterrent. The United States knows we can and will disagree on process, but achieving the peace and security of a world without nuclear weapons will require all of us working together.

In his capstone address before the UN General Assembly last week, President Obama spoke about how no global challenge can be overcome by one country alone. Only through collective action will be able to rollback greenhouse gases that threatens the future of the planet, address a Syrian refugee crisis that has left millions without a home, and yes, “escape the prospect of nuclear war.”

Stopping the spread of nuclear weapons and achieving a world where they are no longer able to threaten our existence will require hard work, cooperation and patience. The United States will continue to do its part and that’s the message we will carry forward at the United Nations in the month to come.

Thank you.