'Striking such systems reduces the enemy's ability to monitor airspace and detect aerial assets in time. The estimated cost of the radar station is about US $100 million,' the General Staff said.

Kyiv's centralised heating systems will be turned on, starting with social institutions such as schools, hospitals, and kindergartens. The decision was sparked by "extreme conditions" created by constant bombardment, Klitschko said.

Zelensky said Poland had provided ammunition used by Ukraine's anti-aircraft guns, but also hinted at other support which would have to remain confidential.