Requests the UN Secretary-General, in coordination with the OPCW Director-General, to submit to the Security Council, for its authorisation, within 20 days of the adoption of this resolution, recommendations, including elements of Terms of Reference, regarding the establishment and operation of an OPCW-United Nations Joint Investigative Mechanism to identify to the greatest extent feasible individuals, entities, groups, or governments who were perpetrators, organisers, sponsors or otherwise involved in the use of chemicals as weapons, including chlorine or any other toxic chemical, in the Syrian Arab Republic where the OPCW FFM determines or has determined that a specific incident in the Syrian Arab Republic involved or likely involved the use of chemicals as weapons, including chlorine or any other toxic chemical, and expresses its intent to respond to the recommendations, including elements of Terms of Reference, within five days of receipt;