The United Nations General Assembly has overwhelmingly approved a trade treaty to regulate international arms.
President Obama, who voted in support of the treaty Tuesday, is expected to sign it within the next few months.
The move sets the stage for a showdown between the National Rifle Association and the White House. Critics say the pact could lead to a national firearms registry and disrupt the American gun market.
The treaty requires countries to take actions to ensure that their arms exports won't be used to harm civilians or violate human rights laws.
"The treaty we have agreed will make trade in conventional arms more responsible and transparent, reduce human suffering, and tangibly contribute to international peace, security and stability," Thomas Mayr-Harting, head of the European Union Delegation to the United Nations, said.
The Obama administration said the treaty applies only to international trade, claiming it will not infringe on the Second Amendment rights of Americans.
But the NRA disagrees. The powerful gun lobby group argues that the treaty violates the Second Amendment, pointing out that among the list of regulated weapons are small arms, which includes rifles and handguns.
Many in the U.S. Senate also oppose the treaty, including eight Democrats who have vowed to block ratification.
A two-thirds majority is required to make the treaty legally binding in the United States.
"Americans will not stand for internationalists limiting and infringing upon their constitutional rights," Sen. James Inhofe, R-Okla., said.
Sen Thad Cochran, R-Miss., also opposes the treaty.
"The Senate has already gone on record in stating that an arms trade treaty has no hope, especially if it does not specifically protect the individual right to bear arms and American sovereignty," he said.
Several U.S. agencies will review the treaty before it is presented to the president for his signature.