Over the 50 years since it first possessed nuclear weapons, China has consistently and continually advocated and promoted the complete prohibition and thorough destruction of nuclear weapons. China's nuclear policy is in harmony with the goals and objectives of the CTBT, and its support for the CTBT will never change. In fact, the efforts and contributions made by China in promoting the entry into force of the treaty are no less than those of the ratified states.

Coming back to the present and looking forward to the future, I believe that the US holds the key that will open the door for the treaty entering into force. We should, as a priority, encourage the US to open the door, instead of staying out of a legally binding instrument.

First of all, the US should undertake its responsibility earnestly. The US has its own difficulties over ratification, which can be understood but cannot be used as an excuse. In recent years, the Barack Obama administration has made some positive commitments on ratification, but it is actions that count. Serious efforts should be made to encourage US lawmakers to change the idea of seeking absolute security at the cost of leaving all other countries feeling insecure, and then to support ratification of the treaty.

Second, joint international efforts should be made to push the US in this direction. The international community, when promoting the entry into force of the CTBT and wider global nuclear governance, should be aware that the stance of the US on the CTBT has an adverse effect on achieving common security. Clear and strong signals in support of early ratification should be sent to the US. The UK and France, as allies of the US, can play a special and important role here.

Third, China and the US could conduct dialogues on CTBT issues. As long as the US adopts a responsible stance, the CTBT can become an important part of promoting China-US strategic mutual trust and building a new model of major-country relations.

Meanwhile, I believe, in upholding the authority of the international nuclear non-proliferation regime and dealing with regional nuclear issues, both China and the US will benefit from the moral and systemic effect brought by the entry into force of the Treaty.

The author is former United Nations under-secretary-general for the department of economic and social affairs.