United Nations member nations have failed to agree on a landmark treaty to regulate global trade in conventional arms.
Iran, North Korea, and Syria blocked adoption on March 28 of a draft, worked out in nine days of talks at the United Nations in New York.
To be approved, the text needed support from all 193 UN member states.
It would require states to review all cross-border arms contracts to ensure weapons won't be used in human rights abuses, terrorism, or violations of humanitarian law.
In his speech outlining Iranian objections, the country’s UN Ambassador Mohammed Khazaee said the draft treaty has "many legal flaws and loopholes" and is "hugely susceptible to politicization and discrimination."
He said the treaty failed to ban transfers of arms to those who "commit acts of aggression" – an apparent reference to rebel groups.
"It is a matter of deep regret that genuine efforts of many countries for a robust, balanced and non-discriminatory treaty were ignored," Khazaee said.
Syrian Ambassador Bashar Ja’afari said the treaty should be more explicit on supplying arms to "terrorists" and "non-state groups."
And North Korea's Deputy Ambassador Ri Tong-il said it could be “politically abused by major arms exporters."
Both Iran and North Korea are under UN arms embargoes over their nuclear programs, while Syria is now in the third year of a civil war.
Diplomats have worked for nearly a decade to agree on a set of principles to regulate the $60 billion global trade in conventional arms.
Talks last July ended in failure, amid sharp divisions over how strict the first binding international treaty on arms trade should be.
The UN General Assembly decided to hold a final conference and set March 28 as the deadline.
Supporters are now expected to take the draft to the UN General Assembly, where it can be passed with a two thirds majority.
U.S. deputy representative Dan Mahley said Washington supported the proposed treaty as "fair and balanced" and looked forward to its quick adoption by the General Assembly.
Calling the draft a "good, strong treaty," British Ambassador Jo Adamson said "This is not a failure, today is success deferred and deferred by not very long."