The head of disarmament at the United Nations warned the international community on Tuesday that the threat of nuclear weapons use has increased because the headway made in the post-Cold War era toward denuclearization has "come to a halt."

"The disarmament and arms control framework upon which the gains of the post-Cold War era were made is eroding, but we have nothing else yet with which to replace it," Izumi Nakamitsu, the U.N. undersecretary general and high representative for disarmament affairs, told Security Council members.

The warning was issued at a meeting to discuss the 1970 Nuclear Non-Proliferation Treaty ahead of the next NPT review conference to be held in 2020, when the landmark pact marks the 50th year since its entry into force. The NPT is reviewed every five years.