UN chemical weapons inspectors are expected to return to Syria on Wednesday, according to Russian government.
Deputy Foreign Minister Sergei Ryabkov said they would investigate alleged chemical weapons attacks at Khan al-Assal, Sheikh Maqsoud and Saraqeb, according to the Interfax news agency.
They had been preparing to do so when chemical weapons were fired at suburbs of Damascus on August 21.
Last week, the UN inspectors confirmed the nerve agent sarin was used in that attack.
They were not asked to ascertain who fired the sarin-filled artillery rockets that hit eastern and western parts of the Ghouta agricultural belt, killing hundreds of people, but Western powers have claimed it could only have been carried out by Syrian government forces.
The Syrian and Russian governments have challenged them to present firm evidence, and instead claimed that rebels were responsible.