Member states failed to reach agreement on a new UN treaty to regulate the multibillion dollar global arms trade, and some diplomats and supporters blamed the United States for triggering the unravelling of the month-long negotiating conference.
Hopes had been raised that agreement could be reached on a revised treaty text that closed some major loopholes by Friday's deadline for action.
But the US announced on Friday morning that it needed more time to consider the proposed treaty - and Russia and China then also asked for more time.
"This was stunning cowardice by the Obama administration, which at the last minute did an about-face and scuttled progress towards a global arms treaty, just as it reached the finish line," said Suzanne Nossel, executive director of Amnesty International USA.
"It's a staggering abdication of leadership by the world's largest exporter of conventional weapons to pull the plug on the talks just as they were nearing an historic breakthrough."
A Western diplomat also blamed the US, saying "they derailed the process", adding that nothing will happen to revive negotiations until after the US presidential election in November. Chief US negotiator Thomas Countryman refused to talk to several dozen reporters when the meeting broke up.
The draft treaty would require all countries to establish national regulations to control the transfer of conventional arms and to regulate arms brokers.
It would prohibit states that ratify the treaty from transferring conventional weapons if they would violate arms embargoes or if they would promote acts of genocide, crimes against humanity or war crimes.
In considering whether to authorise the export of arms, the draft says a country must evaluate whether the weapon would be used to violate international human rights or humanitarian laws or be used by terrorists, organised crime or for corrupt practices.
Many countries, including the US, control arms exports but there has never been an international treaty regulating the estimated 60 billion US dollar (£38 billion) global arms trade. For more than a decade, activists and some governments have been pushing for international rules to try to keep illicit weapons out of the hands of terrorists, insurgent fighters and organised crime.