The United Nations General Assembly on Tuesday signed off on a sweeping, first-of-its-kind treaty to regulate the international arms trade, brushing aside worries from U.S. gun rights advocates that the pact could lead to a national firearms registry and disrupt the American gun market.

The long-debated U.N. Arms Trade Treaty (ATT) requires countries to regulate and control the export of weaponry such as battle tanks, combat vehicles and aircraft and attack helicopters, as well as parts and ammunition for such weapons. It also provides that signatories will not violate arms embargoes, international treaties regarding illicit trafficking, or sell weaponry to countries for genocide, crimes against humanity or other war crimes.

With the Obama administration supporting the final treaty draft, the General Assembly vote was 155 to 3, with 22 abstentions. Iran, Syria and North Korea voted against it.

American gun rights activists, though, insist the treaty is riddled with loopholes and is unworkable in part because it includes "small arms and light weapons" in its list of weaponry subject to international regulations. They do not trust U.N. assertions that the pact is meant to regulate only cross-border trade and would have no impact on domestic U.S. laws and markets.

Critics of the treaty were heartened by the U.S. Senate's resistance to ratifying the document, assuming President Obama sent it to the chamber for ratification. In its budget debate late last month, the Senate approved a non-binding amendment opposing the treaty offered by Sen. James M. Inhofe, Oklahoma Republican, with eight Democrats joining all 45 Republicans backing the amendment.

Sen. Jerry Moran, Kansas Republican, said Tuesday that passing a treaty Iran, Syria and North Korea will just ignore will only serve to constrain law-abiding counties like the U.S.

"The U.S. Senate is united in strong opposition to a treaty that puts us on level ground with dictatorships who abuse human rights and arm terrorists, but there is real concern that the Administration feels pressured to sign a treaty that violates our Constitutional rights," Mr. Moran said. "Given the apparent support of the Obama Administration for the ATT, members of the U.S. Senate must continue to make clear that any treaty that violates our Second Amendment freedoms will be an absolute nonstarter for ratification."

Mr. Inhofe likewise said Mr. Obama should take the Senate vote seriously.

"It's time the Obama Administration recognizes [the treaty] is already a non-starter, and Americans will not stand for internationalists limiting and infringing upon their Constitutional rights," the Oklahoma Republican said. "Furthermore, this treaty could also disrupt diplomatic and national security efforts by preventing our government from assisting allies like Taiwan, South Korea or Israel when they require assistance."

White House spokesman Jay Carney said Tuesday that "we are pleased to join with the consensus" on the treaty, adding that before the White House gets to planning on how to get it through the Senate, it will first review and assess the language of the treaty itself.

Despite the Senate vote, numerous groups have pressured Mr. Obama to support the treaty, and Amnesty International hailed Tuesday's vote.

"The voices of reason triumphed over skeptics, treaty opponents and dealers in death to establish a revolutionary treaty that constitutes a major step toward keeping assault rifles, rocket-propelled grenades and other weapons out of the hands of despots and warlords who use them to kill and maim civilians, recruit child soldiers and commit other serious abuses," said Frank Jannuzi, deputy executive director of Amnesty International USA.

The American Bar Association also released a white paper arguing that the treaty would not affect Second Amendment rights.

General Assembly President Vuk Jeremic said Tuesday that the lack of a regulatory framework on the import and transfer of conventional arms "has made a daunting contribution to ongoing conflict, regional instabilities, displacement of peoples, terrorism and transnational organized crime."

"Whatever the outcome of today's meeting, for a treaty to be effective, we will need to keep working together to fulfill its goals," he said.

Under the treaty, countries must also consider whether weapons would be used to violate international humanitarian or human rights laws, facilitate acts of terrorism or organized crime.

Proponents had hoped that the treaty could be ratified by acclamation at a final negotiating conference last week, but Syria, Iran and North Korea objected.

Some abstaining countries, like India and Egypt, felt the treaty did not go far enough on its language regarding terrorism or human rights.