Negotiations were coming down to the wire at the United Nations Friday to craft a landmark treaty to regulate the $70 billion global arms trade.

The talks in New York are due to end at midnight (0400 GMT Saturday) but the world's biggest arms producers have been haggling over the scope of the conventional weapons treaty. The accord must be agreed on by a consensus of all 193 countries involved in the talks.

Expressing concern over the "very limited progress" made during month-long negotiations, Secretary-General Ban Ki-moon on Thursday urged member states to "show flexibility and work in good faith towards bridging their differences."

A draft treaty circulated Tuesday was severely criticized by rights groups, including Amnesty International and Oxfam, as full of "ambiguities and loopholes," especially in not including ammunition and allowing too much scope for arms transfers that would escape the treaty.

A second draft proposed Thursday evening by Argentine career diplomat Roberto Moritan, who has presided over the negotiations, is an improvement, according to Amnesty International's senior director for law and policy, Widney Brown.

"Some of the significant loopholes that we were concerned about have -- if not been closed -- definitely been narrowed," she explained to AFP.

According to the text, every country must determine if the arms sold may be used to perpetuate human rights violations or terrorism.

A British diplomat said the text represents "a substantial improvement," and that an accord is "now very close."

Diplomats said major concessions are necessary to obtain the signatures of major market players like Europe, the United States, Russia and China.

A small group of states, including Syria, Iran, North Korea and Cuba, have long worked to block a binding treaty and could formally reject the text.

If international players come to a consensus, Moritan will transmit the text to the UN General Assembly.

Individual countries then will decide whether to ratify the treaty, which needs 65 signatures to enter into force.