In a statement, Medvedev said the conflict has effectively been put on hold.
"So who won? First and foremost, common sense, which was severely undermined by the White House's statements about destroying Iranian civilization in a single day," he said.
He said the US willingness to discuss a proposed 10-point plan represented a success for Iran, though the question remains whether Washington will agree to its provisions.
Medvedev warned that Washington needs to maintain the fragile truce with Tehran, as any further move could worsen the situation.
Separately, commenting on the ceasefire, Russian Foreign Ministry Spokeswoman Maria Zakharova said on Wednesday that the approach of an aggressive, unprovoked attack has been defeated, describing the current situation in the Middle East as evidence of the ineffectiveness and unsustainability of any strategy based on escalation and the use of force.
Zakharova said Russia had from the outset called for an immediate cessation to the aggression, stressing the futility of the military approach and the need for a political and diplomatic settlement through negotiations based on international law and respect for the interests of all parties.