A Russian court banned any groups linked to Kremlin critic Alexei Navalny after declaring them "extremist," on Wednesday.
The move bans his allies from elections and comes just days before U.S President Joe Biden and Russian President Vladimir Putin are due to hold talks in Geneva.
Washington has called for Navalny to be freed, and has condemned the recent court decision. But the Kremlin says it is a domestic matter and for the U.S to not interfere.
After a hearing that lasted more than 12 hours behind closed doors, Moscow's prosecutors accused Navalny and his allies of trying to foment a revolution by seeking to destabilize the socio-political situation inside Russia.
A spokesperson for the prosecutors, Alexei Zhafyarov spoke about Navalny's network outside the court:
“This organisation has regularly organised unauthorised mass public events, which frequently have ended with mass unrest."
Navalny and his allies denied the allegations, and said they were an attempt to try to crush any opposition to the ruling party ahead of parliamentary elections in September.
The authorities now have the power to jail activists and freeze their bank accounts if they continue their activities.
The ruling also targets Navalny's Anti-Corruption Foundation which has produced high-profile investigations into alleged official corruption.
Over the years Navalny has built up a vast political network that sought to challenge Putin's grip on power.
In a post on Navalny's Instagram account apparently drafted in anticipation of what was a widely expected ruling, Navalny urged his supporters to not be disheartened.
The message read: "We're not going anywhere."