Russia was able to destroy a key power plant that served Kyiv because Ukraine ran out of defensive missiles, according to Ukrainian President Volodymyr Zelensky. Zelensky’s comments followed repeated warnings from his government about scarce air defenses. Ukraine is calling for more ammunition supplies as Russia scales up its attacks on infrastructure.

The Trypilska thermal power plant is one of the biggest electricity suppliers to the Kyiv region and was destroyed by Russian missiles on April 11. Ukraine was able to destroy the first seven missiles, but the remaining four destroyed the plant. Ukraine has been struggling to convince Western allies to send more air defense systems and is seeking to raise the urgency once more. Russia has staged three big attacks on the country’s electric infrastructure in recent weeks. Kyiv has requested 25 Patriot missile systems to protect its energy systems across the country. Germany said it would deliver a third system to Ukraine in response. The United States and other allies have earlier supplied Patriot systems and missiles.

Read More: Ukraine warns it lacked missiles to protect power plant from Russian attack