“Under no circumstances should this country surrender our gun rights to the control of the United Nations,” Manchin said. “While we can work toward improving the regulation of the international trade of weapons, I am very concerned that the rights of law-abiding Americans would be violated by entering into this agreement.”

Manchin convinced four of his Democratic colleagues to join Republicans in signing the letter — Sens. Mark BegichMark Peter BegichPerez creates advisory team for DNC transition The future of the Arctic 2016’s battle for the Senate: A shifting map MORE (Alaska), Kay HaganKay Ruthven Hagan2020 Dems compete for top campaign operatives Senate GOP rejects Trump’s call to go big on gun legislation Politics is purple in North Carolina MORE (N.C.), Mary LandrieuMary Loretta LandrieuLandrieu dynasty faces a pause in Louisiana Senate GOP rejects Trump’s call to go big on gun legislation Project Veritas at risk of losing fundraising license in New York, AG warns MORE (La.) and Mark PryorMark Lunsford PryorMedicaid rollback looms for GOP senators in 2020 Cotton pitches anti-Democrat message to SC delegation Ex-Sen. Kay Hagan joins lobby firm MORE (Ark.) are all up for tough reelection races in 2014 in red states.

“We write to express our concern and regret at your decision to sign the United Nations’ Arms Trade Treaty,” senators wrote. “We urge you to notify the treaty depository that the U.S. does not intend to ratify the Arms Trade Treaty, and is therefore not bound by its obligations.”

Secretary of State John KerryJohn Forbes KerryJuan Williams: Trump's dangerous lies on Iran Pompeo: US tried, failed to achieve side deal with European allies Trump administration braces for big week ahead in foreign policy MORE signed the treaty last month, saying it wouldn’t harm the rights of U.S. gun owners.

The ATT aims to regulate the nearly $70 billion global trade in conventional arms, but all treaties must be ratified by the Senate. It seems unlikely that Obama has the votes since 53 senators voted in opposition to the treaty as an amendment to the budget resolution in March and a super-majority must ratify treaties.

All Senate Republicans signed the letter with the exception of Sen. Mark KirkMark Steven KirkThis week: Trump heads to Capitol Hill Trump attending Senate GOP lunch Tuesday High stakes as Trump heads to Hill MORE (Ill.), whose home state has some of the highest levels of gun violence in the nation.