UNITED NATIONS (Reuters) - United Nations members on Wednesday were close to a deal on the first international treaty to regulate the $70 billion global conventional arms trade, though delegates and rights groups said India, Iran or others could still block agreement.

Arms control campaigners and human rights groups say one person dies every minute worldwide as a result of armed violence and a treaty is needed to halt the uncontrolled flow of arms and ammunition they say fuels wars, atrocities and rights abuses.

United Nations member states began meeting last week in a final push to end years of discussions and hammer out a binding international treaty to end the lack of regulation over cross-border conventional arms sales.

The world body's 193 member states received the last revision of the draft treaty ahead of the final day of the drafting conference on Thursday.

Reuters questioned delegates from over a dozen countries who said they were cautiously optimistic that the treaty would be adopted unanimously.

"India, Syria and Iran are countries that could still cause trouble," a European diplomat told Reuters on condition of anonymity. "But I'll wager the treaty will pass by consensus."

Iran, which is under a U.N. arms embargo over its nuclear program, is eager to ensure its arms imports and exports are not curtailed, diplomats say. Syria is in a two-year-old civil war and hopes Russian and Iranian arms keep flowing in, they added.

But they are under pressure to back the draft, envoys said.

Speaking on condition of anonymity, a U.S. official declined to say whether Washington would support the draft treaty.

"We are continuing to review the text with an eye toward ensuring that it accomplishes all of our goals, including that it protect the sovereign right of states to conduct legitimate arms trade and, of course, that it not infringe upon the constitutional right of our citizens to bear arms," he said.

Several U.N. diplomats predicted Washington would vote yes.

The National Rifle Association, a powerful U.S. pro-gun lobbying group, opposes the treaty and has vowed to fight to prevent its ratification if it reaches Washington. The NRA says the treaty would undermine domestic gun-ownership rights.

The American Bar Association, an attorneys' lobby group, has said that the treaty would not impact the right to bear arms.

'DEFICIENCIES'

Other major arms producers like Russia and China, which had initially resisted the treaty, along with Germany, France and Britain were also expected to support the draft, diplomats said.

The chief British delegate, Ambassador Joanne Adamson, said the new draft treaty has many improvements over earlier drafts.

"These (improvements) include inclusion of ammunition in the scope of the treaty, a new article on preventing diversion of arms, and strengthened section on exports which are prohibited," she said. "Human rights are at the heart of this text."

The main reason the arms trade talks are taking place at all is that the United States - the world's biggest arms exporter - reversed U.S. policy on the issue after President Barack Obama was first elected and decided in 2009 to support an arms treaty.

The point of an arms trade treaty is to set standards for all cross-border transfers of conventional weapons. It would also create binding requirements for states to review all cross-border arms contracts to ensure arms will not be used in human rights abuses, terrorism or violations of humanitarian law.

Several human rights groups and arms control advocates, including Amnesty International, Oxfam and Control Arms, praised the new draft. They said it had shortcomings, but was a major improvement over an earlier draft that had too many loopholes.

"While there are still deficiencies in this final draft, this treaty has the potential to provide significant human rights protection and curb armed conflict and violence if all governments demonstrate the political will to implement it," Brian Wood of Amnesty International said.

But he made clear that there were problems with the text, including an overly narrow scope of types of arms covered. It covers tanks, armored combat vehicles, large-caliber artillery systems, combat aircraft, attack helicopters, warships, missiles and missile launchers and small arms and light arms.

Predator drones and grenades are among the weapon categories that are not covered explicitly in the draft treaty.

Anna Macdonald of Oxfam said there were "some improvements" in the draft, though some problems remained that she wanted fixed in the final hours before a decision is made by U.N. member states.

"We need a treaty that will make a difference to the lives of the people living in Congo, Mali, Syria and elsewhere who suffer each day from the impacts of armed violence," she said.

Daryl Kimball, head of the Arms Control Association, predicted that "over time, the treaty will help tip the scales in favor of human rights and human security when states consider arms sales in the future."

Rights groups complained about one possible loophole in the current draft involving defense cooperation agreements. Several diplomats who also oppose this loophole said it could exempt certain weapons transfers from the treaty.

Three delegates dubbed that provision the "India clause," because it was something India pushed hard for, they said.

(Reporting By Louis Charbonneau; Editing by Cynthia Osterman and Stacey Joyce