The Obama administration was widely blamed by treaty advocates for derailing the effort back in July when it asked for more time amid growing opposition from Republicans and pro-gun-rights Democrats who are worried the treaty would affect the sale of civilian weapons in the United States. Fifty senators — including eight Democrats — signed on to a letter at the time signaling their opposition to the treaty.

The U.S. Mission said the timing of the vote had nothing to do with the election. They said it was initially scheduled for last week but was delayed because of Hurricane Sandy.

“Our objectives for the ATT have not changed," a Mission official told The Hill. "In particular, we seek a treaty that contributes to international security by fighting illicit arms trafficking and proliferation, protects the sovereign right of states to conduct legitimate arms trade, and meets the concerns that we have been articulating throughout.  As we have made clear, we will not accept any treaty that infringes on the constitutional rights of our citizens to bear arms.”

The treaty sailed through the General Assembly's disarmament committee on Wednesday, with the United States joining 156 other countries in voting to finalize the treaty in March. Russia was the only major arms exporter to vote against.

“This is an opportune moment for all countries to get behind this life-saving treaty to prevent needless suffering worldwide from the unregulated flow of illegal arms,” Amnesty International USA executive director Suzanne Nossel said in a statement.

“The support of five of the 'big six' arms-exporting countries, including the United States, sends a powerful message: these countries can find the political will to stop the mayhem that weapons are causing around the globe. Today's vote is step one toward a hugely meaningful human rights victory. We will be urging the United States and all other countries to keep today's momentum going towards the final passage of the first arms trade treaty.”

The Obama administration has said the treaty would not affect domestic arms sales and would merely require the rest of the world to adopt America's already strong export controls. The treaty would have a hard time being ratified by the Senate, which requires a two-thirds vote, but if the president signs it, that would create some obligations under international law, such as agreeing to refrain from actions that would defeat the treaty's purpose and goals.