Russia is preparing to block the Telegram app over its failure to help government authorities access encrypted messages.

On Friday, a Moscow court ruled in favor of the Russian state communications watchdog Roskomnadzor in its bid to block the messaging app. The watchdog's chief, Aleksandr Zharov, told Russian media he plans on cutting off access to Telegram "soon."

"I won't tell you the exact time when the block on Telegram will begin," he said. "My work is to fulfill this irreproachably in technical terms. This may take days, hours, or minutes."

Roskomnadzor is taking action on Telegram's repeated refusal to comply with Russian law and hand over the encryption keys to its messaging service. The country's Federal Security Service has been demanding the access, citing Telegram's use among terrorists, including by a suicide bomber who killed 15 people in St. Petersburg in April 2017.

In response to Friday's court ruling, Telegram's co-founder Pavel Durov tweeted: "Privacy is not for sale, and human rights should not be compromised out of fear or greed."

According to Durov, complying with Russian demands is "not technically feasible." The messaging service offers end-to-end encryption, meaning that Telegram itself has no access to the content of messages.

Nevertheless, Russian authorities have been pushing Telegram to change its data policies and store user information on local servers that authorities can access. Durov has resisted, claiming that Russia's Federal Security Service wants to expand its influence over the country's citizens.

In a social media post on Russia's VKontakte, Durov said Telegram will use "built-in methods" to try and circumvent the government attempts to block the app.