The Kremlin says officials should review opposition leader Alexei Navalny's calls for an election boycott to see if they might be breaking the law.
In a widely anticipated decision, Russia's top election body voted on Monday to formally bar anti-corruption crusader Mr Navalny from running in the presidential election in March 2018.
Mr Navalny has called on his supporters to boycott the vote in protest.
Despite an implicit ban related to a criminal conviction, Mr Navalny has been campaigning all year, reaching out to the most remote parts of the country.
President Vladimir Putin announced his bid this month.
Mr Putin's spokesman Dmitry Peskov on Tuesday would not comment on the Election Commission's decision to bar Mr Navalny but said the "calls for boycott ought to be carefully studied to see if they are breaking the law."