"Today's announcement does not change the US position on the treaty: the United States does not support and will not sign the 'Treaty on the Prohibition of Nuclear Weapons,'" a State Department spokesman told AFP.
"This treaty will not make the world more peaceful, will not result in the elimination of a single nuclear weapon, and will not enhance any state's security," the spokesman added, stressing that none of the world's nuclear-armed powers had backed the text.
The accord was largely symbolic because none of the nine countries known or suspected of having nuclear weapons -- the United States, Russia, Britain, France, China, India, Pakistan, Israel and North Korea -- put their names down.
The State Department spokesman added that Washington remains committed to its obligations under the Nuclear Non- Proliferation Treaty and to working to "improve the international security environment, prevent and counter proliferation, and reduce nuclear dangers worldwide."