UN member states on Monday will launch talks in New York on drafting the first comprehensive arms trade treaty, which activists say is all the more necessary given the mounting bloodshed in Syria.

Historically, "all the big developments in the control of conventional arms have risen out of scandal and controversy and the political responses to it," said Brian Wood, Amnesty International's arms control chief.

He condemned the "completely irresponsible and reckless decision-making of the Russian government in supplying arms (to Syria) when they know they are going to be used for terrible violations and atrocities."

Moscow and Beijing are Syria's main allies at the UN Security Council, and have routinely opposed international efforts to slap sanctions on President Bashar al-Assad's regime in the wake of a crackdown on dissent that activists say has killed over 15,800 people since March 2011.

They are set to join other governments, like Iran, that are friendly with Syria in opposing plans for the Arms Trade Treaty, which seeks to set criteria to halt the transfer of arms and other equipment that can be used against civilians or to stoke a conflict.

Controls would be the responsibility of states themselves, which would be required to record transactions.

Britain-based rights group Oxfam said the proposed accord should regulate the sales of parts used in military equipment and deadly weapons.

"Many tanks, aircraft carriers and guns are sold in pieces -- just like bookshelves from a furniture store -- with no questions asked about how they are going to be used," said Oxfam's head of arms control Anna MacDonald.

"Buyers can then either put together the pieces themselves, or pay someone else to do the job. That system must end -- buying a tank should not be the same as buying a bookcase."

Most countries acknowledge the need to regulate the huge market, estimated at some $70 billion per year. The United States alone accounts for 40 percent of that total.

But some, like Russia -- which sold some $13.2 billion in military equipment last year -- prefer to focus their efforts on fighting arms trafficking, rather than regulating legal arms sales.

"Much remains unresolved, including the very idea of a binding treaty, its objectives and its scope," a diplomat said, requesting anonymity.

The United States -- which produces six billion bullets a year -- wants to exclude munitions from the treaty, while China doesn't want it to cover small arms, which it exports en masse to developing countries.

According to a UN working draft, India -- the world's biggest arms importer -- Japan, Pakistan and Saudi Arabia insist they must be free to equip their armed forces at will.

China, Russia and Arab countries say the accord's criteria are subjective and politically motivated, while South Korea does not want to hinder technology transfers.

European nations meanwhile have been pushing for a wide-ranging, binding treaty.

"It's in our commercial interests to have other countries abide by the same tough constraints as we do," said a European diplomat.

Wood said that diplomats face an "enormous task" as they try to wrap up the accord by the end of July, expressing worries that the final text would be watered down in the interest of consensus.

If all goes well, he said the treaty could come into force in late 2013, after some three dozen countries ratify the document.