MEXICO CITY (Reuters) – President Barack Obama said on Thursday he will push the U.S. Senate to ratify a long-stalled arms trafficking treaty meant to curb the flow of guns and ammunition to drug cartels in Latin America.

Activists want Washington to push for ratification of the Inter-American Convention against the Illicit Manufacturing of and Trafficking in Firearms, Ammunition, Explosives and Other Related Materials.

The convention, known by Spanish acronym CIFTA, has been languishing in the U.S. Senate since it was adopted in 1997.

Obama, who visited Mexico to show his support for President Felipe Calderon’s efforts to reduce violence and rein in drug cartels, said he would put his weight behind the treaty’s ratification.

“I am urging the Senate in the United States to ratify an inter-American treaty known as CIFTA to curb small arms trafficking that is a source of so many weapons used in this drug war,” he told a joint news conference with Calderon.

Denis McDonough, Director of Strategic Communications at the White House’s National Security Council, told reporters the treaty was on a list that had been submitted to the Senate of treaties the president viewed as priorities.

“This is one of the priority treaties that we’d like to see the Senate’s advise and consent on,” he said.

That may be difficult.

Senate Majority Leader Harry Reid said the United States had to help reduce violence without violating Americans’ right to bear arms, which is enshrined in the Second Amendment of the U.S. Constitution.

“We must work with Mexico to curtail the violence and drug trafficking on America’s southern border, and must protect Americans’ Second Amendment rights,” he said in a statement. “I look forward to working with the President to ensure we do both in a responsible way.”

The treaty has to garner 67 votes in the 100-member Senate, where lawmakers have been loathe to take on the National Rifle Association (NRA), a powerful gun lobby, despite a spate of domestic shootings that have resulted in multiple deaths.

The NRA opposes the treaty.

Wayne LaPierre, NRA executive vice president, said his organization takes “a back seat to no one” in opposing illegal arms trafficking.

“The answer is to enforce the current law. Everything these drug cartels are doing involving firearms is illegal on both sides of the border already,” he told Reuters in a telephone interview.

Jonathan Winer, a former deputy assistant secretary of state who was the main negotiator of the treaty during the Clinton administration, said the treaty would not impose any new restrictions on legal gun sales or ownership in the United States.

“It is designed to help U.S. law enforcement track abuses of firearms of criminals back to the last lawful sale so they can determine what went wrong. It is completely consistent with all U.S. laws and does not ever impose a foreign law on a U.S. person who has abided by U.S. law,” Winer told Reuters.

(Editing by Todd Eastham; additional reporting by Richard Cowan)