A US State Department spokesman expressed concern over the "restrictions on independent voices" in response to the vote by Russia's top electoral body to formally bar Navalny from participating in the 2018 presidential election.
In the wake of US President Donald Trump's surprise electoral victory last year, the US intelligence community said Russia interfered in the election to back its preferred candidate.
Several investigations have been opened with regards to election-meddling, including one probing collusion between the Trump administration and Moscow.
The parliamentary election victory for Putin's United Russia was marred by instances of ballot stuffing, reported by demonstrators on social media.
Anti-Kremlin platform grows Despite being embroiled in legal troubles, Navalny was allowed to run in the 2013 Moscow mayoral election.
Foreign Ministry spokeswoman Maria Zakharova accused the US of "direct interference" in the 2018 presidential election.
On Tuesday, the European Union expressed concerns over the fairness of the upcoming election, saying the decision taken by the electoral commission to bar Navalny "cast serious doubt on political pluralism in Russia.". »
