UNITED NATIONS, May 6 -- China always commits itself to promoting global nuclear governance and supports the international efforts to establish nuclear-weapon-free zones, a Chinese envoy said here on Tuesday.

Liu Jieyi, China's permanent representative to the United Nations, made the remarks after he, on behalf of his country, signed the Protocol to the Treaty on a Nuclear-Weapon-Free Zone in Central Asia which assures five Central Asian nations that nuclear weapons won't be used against them.

"China is the only country that has promised that under no circumstances will it use or threaten to use nuclear weapons against non-nuclear-weapon states and nuclear-weapon-free zones," Liu said, noting that signing the protocol is a concrete reflection of this basic nuclear policy.

He said China actively practices the guideline of "amity, sincerity, mutual benefit and inclusiveness," commits itself to maintaining regional peace and stability, and positively advances its security cooperation with neighboring countries.

"The five Central Asian countries are all friendly neighbors of China," Liu said.

"Signing the protocol is a significant step to implement its neighborhood diplomacy guidelines and to deepen regional security cooperation, which fully demonstrates China's firm commitment to maintaining peace, stability and development of the five Central Asian countries as well as the whole region," he said.

The Chinese envoy also commended Kazakhstan for playing a leading role in the signing process of the protocol. "China will continue to actively support the international efforts to establish nuclear-weapon-free zones in the Middle East, Southeast Asia and other regions," Liu added.

The Treaty on a Nuclear-Weapon-Free Zone in Central Asia, which entered into force in 2009, commits its signatories -- Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan -- to refrain from developing, acquiring or possessing nuclear weapons.

On Tuesday morning, the world's five nuclear powers -- China, France, Russia, the United Kingdom and the United States -- signed the protocol with the five Central Asian countries at the UN headquarters, pledging not to use or threaten to use nuclear weapons or other nuclear explosive devices against any party to the Treaty.