North Korea’s UN envoy said his country was not bound by the non-proliferation treaty (NPT) on nuclear weapons and external pressure would not change its status as a nuclear-armed state, official media reported on Thursday.

Pyongyang threatened to withdraw from the treaty in 1993 and formally did so in 2003. It has since conducted six nuclear tests – prompting a raft of international sanctions – and is believed to possess dozens of nuclear warheads.

Signatories of the NPT have been holding a review meeting of the landmark pact at the United Nations.

There, “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, using North Korea’s official name.

“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.”