Ukrainian leader Vladimir Zelensky issued a warning to every airline that uses Russian airspace, saying any aircraft flying through it will be threatened by Ukrainian drones. President Vladimir Putin called the statement a “declaration of state terrorism.”

The Ukrainian military has been ramping up long-range drone and missile attacks against civilian and infrastructure targets deep inside Russia. The strikes have repeatedly disrupted the work of civilian airports, particularly around Moscow.

On Tuesday, Zelensky claimed that Kiev will close Russian airspace by darkening the skies with drones. “Today, we want to warn every airline that uses Russian airspace, every insurer, and everyone who still uses Russia’s key airports: Russian airspace is becoming completely unsafe,” he said in a video address published on Telegram.

“Safe days in Russia’s skies are over,” he claimed, adding that the threat is addressed to “the airlines currently flying to airports primarily in Moscow, St. Petersburg, and other key destinations in Russia.”

Threats to close Russian airspace amount to a “declaration of state terrorism,” Putin said at a press conference on the sidelines of the Shanghai Cooperation Organization (SCO) summit in Bishkek, Kyrgyzstan. According to the Russian president, these actions make Kiev’s claims about seeking peace talks with Moscow null and void. “One does not hold negotiations with terrorists,” the president said.

Foreign Ministry spokeswoman Maria Zakharova said in Bishkek on Tuesday that the increasing strikes against civilian targets in Russia indicate that Zelensky and “the Kiev regime” are “well aware that such statements are proof of their earlier claims about the supposed desire for peace being false.”

Earlier, Zelensky demanded that the number of strikes on Russia be increased to 1,000 per day. The Russian Defense Ministry regularly reports that it downs hundreds of Ukrainian drones targeting various Russian regions. In mid-August, the ministry reported that it repelled one of the largest Ukrainian drone raids since the beginning of the year, when 822 Ukrainian drones were intercepted and destroyed. Two days later, 791 Ukrainian fixed-wing UAVs were downed overnight across the country.

Russia has also conducted long-range strikes on military targets in Ukraine in response to repeated attacks on civilian and energy infrastructure in Russia. Moscow stated that Kiev’s “terrorist” tactics are aimed at diverting the attention of the public from Ukrainian setbacks on the battlefield.