Ukrainian President Volodymyr Zelenskyy said in a Tuesday night address that Russian airspace has become “completely unsafe” for aviation because of Ukrainian drones. He warned airlines, insurers and users of Russia’s key airports to consider the growing drone presence, while saying Ukraine was not threatening civilian aviation or any civilian aircraft.

Zelenskyy said skies filled with drones could not be safe for civilian flights and would remain under drone pressure as long as the war continued. Ukrainian drone activity has repeatedly disrupted flights at Russian airports in recent months, alongside an increase in such attacks. Russian President Vladimir Putin called Zelenskyy’s remarks a declaration of “state terrorism” and said terrorists could not be negotiated with.

The exchange came as renewed Russian missile and drone attacks killed at least 12 people in Kyiv and nearby areas. Zelenskyy said Ukraine did not want innocent people to die and was warning partners that safe days in Russian skies were over. Putin acknowledged damage inside Russia from Ukrainian strikes, including against oil refineries and civilian facilities, saying the sites had not been adequately protected. He also claimed Russia was advancing on the battlefield.