Pyongyang first withdrew from the Non-Proliferation Treaty in 1993 and has since conducted six nuclear tests, subjecting it to multiple United Nations resolutions, and is believed to possess dozens of nuclear warheads.

"At the 11th NPT Review Conference currently under way at UN headquarters, the United States and certain countries following its lead are groundlessly calling into question the current status and exercise of sovereign rights" of North Korea, Pyongyang's top UN envoy Kim Song said in a statement carried by the official Korean Central News Agency.

"The status of the Democratic People's Republic of Korea as a nuclear-armed state will not change based on external rhetorical claims or unilateral desires," he added.

"To make it clear once again, the Democratic People's Republic of Korea will not be bound by the Non-Proliferation Treaty under any circumstances whatsoever."

He continued that the country's status as a nuclear-armed state has been "enshrined in the constitution, transparently declaring the principles of nuclear weapons use".

North Korea has consistently insisted that it will not give up its nuclear arsenal, describing its path as "irreversible" and vowing to strengthen its capabilities.

Pyongyang has sent ground troops and artillery shells to support Russia's invasion of Ukraine, and observers say Pyongyang is receiving military technology assistance from Moscow in return.

The nine nuclear-armed states -- Russia, the United States, France, the United Kingdom, China, India, Pakistan, Israel and North Korea -- possessed 12,241 nuclear warheads in January 2025, the Stockholm International Peace Research Institute reported.

The US and Russia hold nearly 90 percent of nuclear weapons globally and have carried out major programs to modernise them in recent years, according to SIPRI.