Russia and China on Tuesday (May 13th) boycotted what Moscow called an "unacceptable" closed-door videoconference with the UN Security Council on chemical weapons in Syria.

"Russia and China have empty tiles" on the screen, a Security Council member told AFP, speaking on condition of anonymity.

During the meeting, council members were to hear reports from the UN's top representative for disarmament affairs, Izumi Nakamitsu, and Organisation for the Prohibition of Chemical Weapons (OPCW) head Fernando Arias.

The Security Council also was to hear from Santiago Onate-Laborde, the co-ordinator of the OPCW's Investigation and Identification Team (IIT) that was started in 2018.

In early April, the IIT published a report for the first time explicitly blaming the Syrian regime for three chemical weapons attacks in 2017.

According to regime ally Russia, the Syrian regime had halted its chemical weapons programme, destroyed its stockpile of chemical weapons and its production capacity.

The Syrian regime has denied responsibility for the 2017 attacks.

Tuesday's meeting "has been scheduled in a closed format to allow council members and the Syrian Arab Republic to exchange views frankly and ask questions to the briefers", the UK's UN diplomatic mission said in a statement.

"A refusal to attend the meeting and engage with the OPCW on the substance of its findings is disappointing and indicative of the preference of some council members to undermine the prohibition on chemical weapons use by attacking the people and institutions charged with protecting it," the statement said.