When United Nations Secretary-General Antonio Guterres warned on Monday that "humanity is just one misunderstanding, one miscalculation away from nuclear annihilation," he was not raising a false alarm.

Speaking at the opening of the long-delayed high-level meeting to review the landmark Treaty on the Non-Proliferation of Nuclear Weapons, he said it was taking place "at a time of nuclear danger not seen since the height of the Cold War".

As the cornerstone of the international nuclear disarmament and non-proliferation regime and an integral component of the post-war international security architecture, the NPT is facing old and new challenges as the global strategic security environment continues to deteriorate on many fronts.

The 2015 Iran nuclear deal remains in tatters after the US withdrawal, despite efforts to shore it up. Denuclearization of the Korean Peninsula seems as remote as ever, despite developments under the previous US administration raising hopes of a breakthrough. The Ukraine crisis has created renewed fears of a potential nuclear confrontation, or accident. And the fear of nuclear terrorism remains.

Worse, the United States, which boasts one of the world's largest and most advanced nuclear arsenals, has been behaving in an increasingly irresponsible manner that poses a threat to global strategic security. It is investing trillions of dollars in developing low-yield nuclear weapons while lowering the threshold for its use of nuclear weapons. It has also withdrawn from one international treaty after another, including the Iran nuclear agreement, and is creating a nuclear clique in the Asia-Pacific region by forming AUKUS, a security alliance with the United Kingdom and Australia. Under this framework the US and the UK will supply nuclear-powered submarine technology to Australia. As others have pointed out, this breaches the letter and spirit of the NPT. The US should act responsibly and diminish the importance of nuclear weapons in its national security policy and substantively reduce its nuclear arsenal so that other nuclear-weapon states follow suit.

It should also work with relevant parties to resolve the remaining differences in the Vienna talks aimed at reviving the Iran nuclear deal. The current US administration promised the US would return to the Iran deal and support multilateralism. It should act to show that it was not just making empty promises.

The parties involved in the latest international efforts to firmly uphold the universality, authority and effectiveness of the NPT should do their utmost to produce a positive result that helps advance nuclear disarmament, non-proliferation and peaceful uses of nuclear energy, and add new vigor to the NPT's role in safeguarding peace and stability.

All concerned should stay committed to the right direction and step up their efforts to strive for consensus on outstanding issues so that real progress can be made in preventing the spread of nuclear weapons and achieving the goal of nuclear non-proliferation.