UNITED NATIONS (Reuters) - Negotiators from around 150 countries gather in New York on Monday for a final push to hammer out a binding international treaty to end unregulated conventional arms sales, a pact that a powerful U.S. pro-gun lobby is urging Washington to reject.

Arms control campaigners and human rights advocates say one person every minute dies worldwide as a result of armed violence, and that a treaty is needed to halt the uncontrolled flow of weapons and ammunition that they argue helps fuel wars, atrocities and rights abuses.

The U.N. General Assembly voted in December to relaunch negotiations this week on what could become the first global treaty to regulate the world's $70 billion trade for all conventional weapons - from naval ships, tanks and attack helicopters to handguns and assault rifles - after a drafting conference in July 2012 collapsed because the United States, then Russia and China, wanted more time.

Delegates to the July conference said that Washington had wanted to push the issue past the November 2012 presidential election, though the administration of President Barack Obama denied that. The current negotiations will run through March 28.

The United States says it wants a strong treaty. But Obama is under pressure from the powerful National Rifle Association, the leading U.S. pro-gun group, to block the pact. The group has vowed to torpedo the convention's Senate ratification if Washington backs it at the United Nations.

U.S. Secretary of State John Kerry voiced conditional support for the treaty on Friday, saying Washington was "steadfast in its commitment to achieve a strong and effective Arms Trade Treaty that helps address the adverse effects of the international arms trade on global peace and stability.

But he did not promise U.S. support. He repeated that the United States - the world's No. 1 arms manufacturer - would not accept a treaty that imposed new limits on U.S. citizens' right to bear arms, a sensitive political issue in the United States.

The NRA has dismissed suggestions that a December U.S. school shooting massacre in Connecticut bolstered the case for a global arms pact. It has also warned that the treaty would undermine U.S. citizens' right to own guns, a position that supporters of the treaty say is false.

The American Bar Association, an attorneys' lobbying group, last month disputed the NRA position, saying in a paper "ratification of the treaty would not infringe upon rights guaranteed by the Second Amendment."

AMMO: 'THE FUEL OF CONFLICT'

The point of the treaty is to set standards for all cross-border transfers of any type of conventional weapon - light and heavy. It also would set binding requirements for nations to review all cross-border arms contracts to ensure the munitions will not be used in human rights abuses, do not violate embargoes and are not illegally diverted.

"Syria, Mali, the Democratic Republic of the Congo and Sri Lanka are just a few recent examples where the world bore witness to the horrific human cost of a reckless global arms trade steeped in secrecy," Salil Shetty, secretary general of Amnesty International, said on Monday.

The United States accounts for around 30 percent of the world's arms exports, followed by Russia with 26 percent, according to the Stockholm International Peace Research Institute. Germany and France are in third and fourth place, with China having replaced Britain as No. 5, it said.

If the conference fails to agree a treaty in the next 10 days because it fails to reach the required consensus, diplomats say they can put it to a vote in the U.N. General Assembly to rescue it.

The draft treaty focuses solely on international arms transfers. If a pact is approved in New York, it will require ratification by national legislatures before it can take effect.

U.N. Secretary-General Ban Ki-moon called for commonly accepted standards for arms and ammunition. "These standards are important for assessing the risks that transferred weapons are not used to fuel conflict, arm criminals or abet violations of international humanitarian or human rights law," he said.

Negotiations will not be easy, U.N. diplomats say. Washington opposes inclusion of ammunition in the treaty. Rights groups and arms control advocates hope the U.S. delegation will compromise on the question of ammunition.

"Ammunition is literally the fuel of conflict," said Roy Isbister of Saferworld, a peace lobby group. "Without ammunition, the guns fall silent."

Rights groups have urged delegations to repair loopholes in the draft treaty, which they say could leave avenues for abusers of human rights to continue getting weapons.

They say the partial coverage of ammunition in the current draft is a major weakness. Rights groups say that the global ammunitions industry for small arms and light weapons is worth $4.3 billion, with 12 billion bullets produced each year.