US President Donald Trump has said he will withdraw his country from the international Arms Trade Treaty.
The agreement, signed by Barack Obama in 2013, aims to regulate the sale of weapons between countries.
The US National Rifle Association says the treaty amounts to international gun control, and is a threat to America's second amendment right to bear arms.
Speaking at the lobbying group's annual meeting, Mr Trump said he would ask the US Senate not to ratify the pact.
The US is the world's top arms exporter. Its weapons sales are 58% higher than those of Russia, the world's second largest exporter.
"We're taking our signature back," the president said at the meeting in Indianapolis, adding that the UN would soon receive formal notice of the US's withdrawal from the Arms Trade Treaty (ATT).
"Under my administration, we will never surrender American sovereignty to anyone," he said. "We will never allow foreign bureaucrats to trample on your second amendment freedoms."
In a statement released after Mr Trump's speech, the White House said the treaty "fails to truly address the problem of irresponsible arms transfers" because other top arms exporters - including Russia and China - have not signed up to it.
UN officials told Reuters news agency that the organisation was previously unaware that Mr Trump was planning to take the US out of the pact.