Answering the question about "how Moscow assesses this event", he said that "as a political performance that will not affect the international legal reality formed by the free expression of the will of the Crimeans."
Earlier, Russian Foreign Minister Sergei Lavrov called the Crimean Platform forum planned by the Ukrainian authorities a Sabbath.
The summit is scheduled to take place on 23 August.
Crimea became a Russian region after a referendum in March 2014, in which a majority of residents voted in favor of reunification with Russia.