A top UN official denounced growing rhetoric claiming that nuclear arms are necessary and warned that the risk of such weapons being used was on the rise.

"The threat of the use, intentional or otherwise, of nuclear weapons is growing," the UN’s representative for disarmament affairs,  A top UN official ,Izumi Nakamitsu, told a preliminary review meeting of the Nuclear Non-Proliferation Treaty (NPT).

Speaking at the opening of the Geneva meeting, Nakamitsu warned that "the world today faces similar challenges to the context that gave birth to the NPT." The NPT treaty, which counts 191 state parties, faces a comprehensive review every five years, with preparatory committees each year in between.

Nakamitsu hailed the announcement, voicing hope that the move "will contribute to building trust and to sustaining an atmosphere for sincere dialogue and negotiations." Other speakers at the opening of the Geneva meeting, including the European Union representative, stressed the need to "keep pressure" on North Korea.

Nakamitsu also cautioned that the overall "geopolitical environment is deteriorating." "Some of the most important instruments and agreements that comprise our collective security framework are being eroded," she said.

"Rhetoric about the necessity and utility of nuclear weapons is on the rise," she said, stressing that "modernisation programmes by nuclear-weapons states are leading to what many see as a new, qualitative arms race."

Nakamitsu noted that until recently all the major powers have been engaged in "continuous and successive negotiations on arms control and disarmament". "Yet not only have we seen an unfortunate hiatus in these efforts, there are real concerns that unless we reverse this trend we will soon be back in a situation for the first time in which there are no verified constraints on nuclear arsenals," she said.

Meanwhile Nuclear arms policymakers are in Geneva right now getting set for a review of the Nuclear Non-Proliferation treaty in 2020.

Delegates there have also raised concern about the idea of the US scrapping the Iran agreement.

They expressed the concerns in Geneva on Tuesday, the second day of a preparatory meeting for the 2020 Nuclear Non-Proliferation Treaty Review Conference.

Delegates from Britain, Sweden and other countries said that a US withdrawal from the accord would have a serious impact on the global efforts for nuclear disarmament and non-proliferation.Iran's representative said the country will not respond to a renegotiation or revision of the deal, and it will show the world how untrustworthy Washington is in international negotiations.

Russia's representative said a breach of the nuclear agreement would defy the will of the international community, make North Korea distrust the US, and make it more difficult to denuclearize the Korean Peninsula.

US President Donald Trump is expected to decide by May 12th whether to leave the 2015 deal.

Five of the world’s nine nuclear-armed states -- Britain, China, France, Russia, and the United States -- are parties to the NPT. India and Pakistan, as well as Israel, which has never acknowledged it has nuclear weapons, have never signed the treaty.

But despite their treaty obligations, observers say that all nuclear-armed NPT members are engaged in modernising their arsenals and making nuclear weapons a more central part of their defence strategies.

President Donald Trump’s administration has for instance recently decided to upgrade the US nuclear weapons arsenal and to complement massive "strategic" bombs with smaller "tactical" weapons, in a move critics say would make them easier to use.