"We've warned and warned the US that these plans must be unconditionally refused. Any such unlawful use of force, similar to what happened almost a year ago at the Shairat air base, would be an act of aggression against a sovereign state, as defined by the relevant article of the UN Charter," he said.
Sergei Ryabkov believes that if the situation in Syria and, in particular, Eastern Ghouta changes for the better, opponents to a peaceful resolution to the conflict could incite the international community by sabotaging this process, possibly by using chemical weapons.
"The situation in Eastern Ghouta has changed radically for the better," Sergei Ryabkov told reporters on Tuesday.
He drew attention to the fact that tens of thousands of people had already left the danger zone. "All this, of course, infuriates, in the truest sense of the word, the opponents of the government in Damascus; they are looking for new pretexts for attacks on us and on Syria," Ryabkov said.
"In this situation, of course, any provocations are possible, and we need to be prepared. Provocations could include staging the use of chemical weapons by government troops," Ryabkov said.
London still refuses to cooperate with Moscow in the investigation of the poisoning of the former Russian double-agent Sergei Skripal, which Russian Deputy Foreign Minister Sergei Ryabkov has described as a massive provocation.
"The British, acting with explicit malicious intent, have delivered some accusations. Once again, without backing them in any way with material evidence, with any kind of basis, rejecting cooperation, and, most outrageously, successively depriving us of consular access to Russian citizen Julia Skripal, who, as we understand, is in a critical state," Ryabkov told reporters.
"All this is nothing more than a large-scale, multi-layer provocation, which is being conducted via a whole series of unlawful methods," the deputy head of the Russian Foreign Ministry added.
Moscow once again declares that neither Russia nor the USSR had a program for the development and production of chemical weapons under the conventional name "Novichok," Russian Deputy Foreign Minister Sergei Ryabkov stressed.