Telegram founder Pavel Durov said Thursday that Russian authorities had designated him a "terrorist" after he refused to comply with Moscow's demands for mass surveillance and censorship on the messaging platform, accusing the Kremlin of seeking tighter control over online communications.

"Russia has designated me as a 'terrorist' for refusing its demands for mass surveillance and censorship on Telegram," he said on his platform.

Earlier Thursday, Russia added Durov, 41, to a blacklist of "terrorists and extremists," a day after saying it was seeking his arrest over accusations he let his platform be used by Ukrainian intelligence.

Durov, who has lived outside Russia for years, holds French and United Arab Emirates passports.

He said that under Russian law, he was now banned from 'publishing information on the Internet."