U.N. Security Council members China and Russia, as well as Serbia, have continued supplying Myanmar's junta with weapons used to attack civilians since last year's coup, a U.N. rights expert said Tuesday.

United Nations Special Rapporteur on the rights situation in Myanmar, Tom Andrews, urged the Security Council to convene an emergency session "to debate and vote on a resolution to, at a minimum, ban those arms transfers that the Myanmar military are known to use to attack and kill Myanmar civilians."

He released a long-awaited report Tuesday detailing where the junta is getting its weapons from, highlighting that two permanent members of the Security Council itself, who hold veto power over its decisions, remain among the main suppliers.

"Despite the evidence of the military junta's atrocity crimes being committed with impunity since launching a coup last year, U.N. Security Council members Russia and China continue to provide the Myanmar military junta with numerous fighter jets, armored vehicles, and in the case of Russia, the promise of further arms," Andrews said in a statement.

"During this same period, Serbia has authorized rockets and artillery for export to the Myanmar military," said Andrews, who is an independent expert appointed by the U.N. Human Rights Council, but who does not speak on behalf of the world body.

"It is imperative that member states and the Security Council act urgently to stop weapons sales to the military junta. Human lives, and Security Council credibility, are on the line," he said. "The Security Council should consider, at the very least, a resolution to ban weapons that are being used by the Myanmar military to kill innocent people."

Myanmar has been in chaos, its economy paralyzed, and more than 1,500 civilians have been killed in a military crackdown since the putsch in February 2021, according to a local monitoring group.