THE United States is pressing countries to withdraw from a United Nations treaty banning nuclear weapons as the pact comes close to achieving the 50 ratifications required for it to come into force.

The prospect of the threshold being reached within days has prompted President Donald Trump’s administration to write a letter warning governments that the world’s five original nuclear powers – the US, Russia, China, Britain and France – along with Washington’s Nato allies, “stand unified in our opposition to the potential repercussions” of the treaty taking effect.

The three-year-old Treaty on the Prohibition of Nuclear Weapons (TPNW) – also known as the nuclear ban treaty – requires signatories to “prohibit the development, testing, production, stockpiling, stationing, transfer, use and threat of use of nuclear weapons.”

It contains a legal framework for negotiations on the verified and irreversible elimination of nuclear weapons programmes to begin once it has received the support of 50 signatories – and up to October 13 some 47 nations had endorsed it.

The US insists that the treaty “turns back the clock on verification and disarmament and is dangerous” to the Non-Proliferation Treaty, which has been widely criticised for containing only partial prohibitions.

The US claim has been dismissed by Beatrice Fihn, director of the International Campaign to Abolish Nuclear Weapons, as “straightforward lies.”

“They have no actual argument to back that up,” she said. “The Non-Proliferation Treaty is about preventing the spread of nuclear weapons and eliminating nuclear weapons, and this treaty implements that.

“There’s no way you can undermine the Non-Proliferation Treaty by banning nuclear weapons. It’s the end goal of the Non-Proliferation Treaty.”

“That the Trump administration is pressuring countries to withdraw from a United Nations-backed disarmament treaty is an unprecedented action in international relations,” Ms Fihn added.

“That the US goes so far as insisting countries violate their treaty obligations by not promoting the TPNW to other states shows how fearful they are of the treaty’s impact and growing support.”

She insisted that the “increasing nervousness, and maybe straightforward panic, within some of the nuclear-armed states and particularly the Trump administration” shows that they “really seem to understand that this is a reality: nuclear weapons are going to be banned under international law soon.”