The Ministry's spokeswoman Maria Zakharova said Russian Foreign Minister Sergey Lavrov plans to participate in the meeting of the group, which includes 17 countries.
US Secretary of State John Kerry also confirmed in statements to reporters in London on Tuesday that the ISSG is to meet in Vienna on May 17.
"The ISSG will formally come together to build on what we did with the Russians in terms of this agreement and to talk about all kinds of things, ranging from duration, to enforcement to the political process," Kerry added.
He said that he expected talks involving the opposing [Syrian] parties to take place "some days after that".
SANA/MNA