Ukrainian President Volodymyr Zelenskyy said on Monday that Russia is planning a protracted campaign of drone attacks in a bid to demoralize Ukraine.

Speaking from Kyiv in his nightly address and quoted by the BBC, Zelenskyy said he had received intelligence reports suggesting that Moscow would launch the attacks using Iranian-made Shahed drones.

The Ukrainian leader added that Russia planned to “exhaust” Ukraine with a prolonged wave of drone attacks.

“We must ensure – and we will do everything for this – that this goal of terrorists fails like all the others,” he said, according to the BBC. “Now is the time when everyone involved in the protection of the sky should be especially attentive.”