The United Nations called for a halt of weapons to Myanmar on Friday.
U.N. Secretary-General Antonio Guterres urged the military to respect November election results and to release political detainees, including leader Aung San Suu Kyi.
The military has called the election a fraud, despite international observers saying the ballot was fair.
Four months since the military seized power in a coup on February 1, the U.N General Assembly adopted a resolution - after watering down an initial draft with stronger language calling for an arms embargo.
Nine Southeast Asian countries called for the language to be removed.
Instead they agreed on calling on member states to quote "prevent the flow of arms into Myanmar."
Myanmar's U.N Ambassador Kyaw Moe Tun said the decision was long overdue:
"We are so disappointed that it took almost three months to adopt this watered down resolution even though it does not include many important points, to save lives of the people in Myanmar."
The U.N. special envoy on Myanmar also warned that "the opportunity to reverse the military takeover is narrowing" and the risk of a large-scale civil war.
The junta's forces have killed more than 860 people since the coup, according to the Assistance Association for Political Prisoners.