Image caption Pro-treaty campaigners set up a mock graveyard for arms' victims near the UN building in New York

Negotiations at the UN to achieve a landmark treaty to regulate the conventional arms trade have ended without agreement.

The US, followed by Russia and China, said they needed more time to consider the issues.

The BBC's Barbara Plett at the UN said it was a disheartening end to a month of intense negotiations.

However, the conference chairman said he was confident a treaty could be agreed by the end of the year.

Some delegates accused the US of bowing to domestic pressure from the powerful gun lobby in the run up to presidential elections, our correspondent says.

On Thursday, a bipartisan group of 51 US senators threatened to oppose any agreement that infringed on the constitutional right to bear arms.

Despite the setback, conference chairman Roberto Garcia Moritan said the eventual adoption of an Arms Trade Treaty (ATT) was inevitable.

"I don't have any doubt, because there is a need," he said.

"We need a treaty and we will have a treaty."

WORLD'S TOP ARMS SUPPLIERS United States

Russia

Germany

France

United Kingdom Source: Stockholm International Peace Research Institute

UN Secretary-General Ban Ki-moon said he was disappointed at the failure to agree on a treat and called it "a setback".

But he said he was encouraged that countries had agreed to continue pursuing a treaty and pledged his "robust" support.

The negotiations were the result of a six-year campaign by a coalition of non-governmental organisations, including Amnesty International and Oxfam.

Amnesty Secretary-General Salil Shetty expressed frustration at the delay.

"With one person dying every minute because of armed violence, there is an imperative for powerful states to lead," he said.

"President Obama has asked for more time to reach an agreement. How much more time does he want?"

The text of the draft resolution is now likely to be sent back to the UN General Assembly in the autumn.

The global arms trade is estimated to be worth between $60bn and $70bn (£40-50bn) per year.

Some 750,000 people are killed by illicit weapons each year.