Russia's telecommunications watchdog Roskomnadzor has threatened to completely block WhatsApp in the country following previous restrictions on the messaging service.

If WhatsApp does not meet the requirements of Russian legislation, it will be blocked, the state news agency TASS quoted Roskomnadzor as saying in a statement on Friday.

In the past, the authority has argued that criminals use WhatsApp for extortion, fraud and involving Russian citizens in acts of sabotage.

Calls via WhatsApp and Telegram have been restricted in Russia for some time, and the encrypted service Signal and the messenger Viber were already blocked in 2024.

Foreign messaging services are to be replaced by the state-preferred app Max, which critics fear will give the authorities access to data.

Moscow has been increasingly tightening control and censorship on the internet, especially since the start of the full-scale invasion of Ukraine more than three and a half years ago.

In July, the Russian parliament decided that searching for information classified as "extremist" by the authorities would also be punishable by a fine of up to 5,000 roubles ($64).

Internet resources that criticize the ruling establishment, such as the Anti-Corruption Fund of Kremlin opponent Alexei Navalny, who died in custody in February 2024, are particularly likely to be branded as "extremist."