Russia and China on Tuesday boycotted what Moscow called an "unacceptable" closed-door video conference of the UN Security Council on chemical weapons in Syria.
Russia's UN ambassador, Vassily Nebenzia, later said Moscow wanted the discussion to be open.
"Regrettably, our western partners and their allies insisted on holding this meeting behind closed doors in an informal setting, despite the slogans of openness and transparency of the Security Council," Mr Nebenzia said.
"Such an approach is unacceptable to us as it undermines the prerogatives of state parties to the Chemical Weapons Convention."
During the monthly meeting, Council members heard reports from the UN's top representative for disarmament affairs, Izumi Nakamitsu, and the head of the Organisation for the Prohibition of Chemical Weapons, Fernando Arias.
The Council also heard from Santiago Onate-Laborde, co-ordinator of the OPCW investigation and identification team that was started in 2018.
In early April the team published a report for the first time explicitly blaming Damascus for three chemical weapons attacks in 2017.
to Moscow, a Damascus ally, said Syria had halted its chemical weapons programme, and destroyed its stockpile and its production plants.
Damascus has denied responsibility for the 2017 attacks.
The UK's mission to the UN said Tuesday's meeting was behind closed doors to allow members and Syrian representatives to exchange views frankly and ask questions of those briefing on the situation.
"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 UK mission said.
During the meeting, Jonathan Allen, UK ambassador to the UN welcomed the report and said there should be no impunity for chemical weapons attacks in Syria.
"The findings, those clear conclusions, are that units of the Syrian Air Force were responsible for three chemical weapons attacks in Ltamenah in Syria in March 2017," Mr Allen said.
"That adds to the facts collected by two separate previous investigations mandated by this council, which also found that the Syrian regime used chemical weapons against its own people on at least four separate occasions."
"It is imperative that the Security Council shows leadership in demonstrating that impunity, and the use of these weapons, will not be tolerated."
