The United States, Britain and France have asked for the U.N. Security Council to discuss the issue of Russia using Iranian drones in the war in Ukraine.

Diplomats said Tuesday the request included asking for a U.N. official to brief the council during a closed-door meeting Wednesday.

Ukrainian officials have said drones used in waves of attacks during the past week, including on Ukraine’s capital, Kyiv, were Iranian-made Shahed-136 attack drones that Russia used to carry explosives and crash into their targets.

Iran has denied supplying the drones to Russia, and Russian officials have denied using them.

Estonian Defense Minister Hanno Pevkur told reporters Tuesday he expects more drone attacks against “many cities in Ukraine.”

Pevkur said Ukraine has managed to shoot down about half of attacking drones, but that it still needs more help. Ukrainian officials have in recent days repeated their calls for allies to provide more air defense aid.

Ukraine’s foreign ministry said that in the past week alone, more than 100 Iranian-made drones have slammed into power plants, sewage treatment plants, residential buildings, bridges and other targets in urban areas.

Andriy Yermak, the head of Ukrainian President Volodymyr Zelenskyy’s office, said Wednesday Russia is “trying to scare the people of Kherson with fake messages about the shelling of the city by our army and are also staging a propaganda show with evacuation.”

Russia’s new commander in Ukraine, Sergei Surovikin, told the state-owned Rossiya 24 television news channel said Russia plans to evacuate civilians ahead of Ukraine’s offensive to reclaim Kherson, one of four regions under Russian control.

Surovikin called Tuesday for an “organized, gradual displacement” of civilians from four towns on the Dnipro River, a 2,200-kilometer-long river that bisects Ukraine.

He also said the situation in the Kherson region is “very difficult” as Ukrainian forces wage an offensive to retake southern and eastern areas that Moscow illegally annexed last month.