President Donald Trump withdrew the U.S. on Friday out of another treaty aimed at curtailing the global proliferation of weapons.
Trump told a gathering of the pro-gun rights National Rifle Association his administration "will never surrender American sovereignty to anyone," pointing to the Arms Trade Treaty.
"We will never allow foreign bureaucrats to trample on your Second Amendment freedoms. And that is why my Administration will never ratify the UN Arms Trade Treaty," Trump said, referring to the article of the Constitution that guarantees Americans' right to bear arms.
The Arms Trade Treaty regulates the international trade of conventional firearms. While the U.S. has signed on to the pact, it has not been ratified by Congress.
Trump signed on stage a message to the Senate asking it to stop the ratification process and return the treaty to him so he can "dispose" of it.
"By taking these actions we are reaffirming that American liberty is sacred, that American citizens live by American laws, not the laws of foreign countries," Trump said.
The treaty seeks to thwart illicit arms sales to individuals and groups accused of carrying out gross rights abuses. But key international players like Russia and China never signed on to the pact.
Critics of the agreement have argued it could threaten U.S. sovereignty.
But following his announcement, Amnesty International USA said the pact "in no way interferes" with the American right to bear arms.
"As the biggest arms exporter, the US signature to the ATT was an important step towards ensuring that dangerous weapons stay out of the wrong hands," Adotei Akwei, Amnesty USA's deputy director for government relations, said in a statement.
"With this announcement the Trump administration will re-open the floodgates for arms sales with weakened human rights criteria, which could potentially fuel brutal conflicts, and make everyone less safe,” he added.
By Michael Hernandez in Washington