The anti-corruption organization of the imprisoned Kremlin critic Alexey Navalny has announced that it will reopen its offices in Russia.

The aim is to fight against "mobilization and the war" in Ukraine, announced exiled Navalnyj confidant Ivan Zhdanov on Tuesday in a video published online.

The partial mobilization "brought suffering to every Russian family," said Leonid Volkov, a confidant of Navalnyj who is also living in exile.

Russian authorities classified Navalny's organizations as "extremist" in late June after months of increasing repression, leaving staff, volunteers and sympathizers at risk of prosecution and imprisonment.

The 46-year-old Navalnyj is the best-known critic of President Vladimir Putin in Russia.

He is currently serving a nine-year sentence in a penal colony.