Ukraine’s President Volodymyr Zelensky has warned airlines and passengers against using Russian airspace, saying it will be filled with Ukrainian drones for the duration of the war.

“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,” Mr Zelensky said on Tuesday.

The Ukrainian president, who vowed to escalate drone attacks on a large scale, insisted that attacks from Russia will trigger stronger retaliation.

He added, “There will simply be drones in Russia’s skies on a scale that has to be taken into account. Although the Russian authorities are not properly informing people about this, Russian airspace will effectively be closing – the war started by Russia is closing its skies.”

Mr Zelensky said the warning was meant to ensure no innocent lives were lost, urging ambassadors in Ukraine to convey the information to their capitals.

“We in Ukraine do not want innocent lives to be lost. That is why we are warning our partners: the safe days in Russia’s skies are over. It is important that this is heard by the ambassadors of countries represented here in Ukraine, as well as by ambassadors working in Moscow.

“Every one of them knows exactly what Russia’s war means for our country and our people, and they must convey this information to their capitals. It is important that the airlines currently flying to airports primarily in Moscow, St. Petersburg, and other key destinations in Russia hear this as well,” stated the Ukrainian president.

Mr Zelensky’s warning came amid escalating Russian attacks on Ukraine, with heavy strikes killing scores of people on Monday.

President Vladimir Putin described Mr Zelensky’s threat as a “declaration of state terrorism”, noting that Russia would continue its own intensifying attacks on Ukraine.

“Ukraine does not threaten civilian aviation as such—not a single civilian aircraft. There will simply be drones in Russia’s skies on a scale that has to be taken into account,” Mr Putin stated on Tuesday.