As deadly Russian airstrikes continued into a second day, Ukrainian President Volodymyr Zelensky on Tuesday asked the Group of 7 nations to help his country establish an “air shield” against aerial attacks.

Zelensky’s plea comes amid one of the fiercest bombing campaigns that Russia has waged against Ukraine since invading in late February. At least 19 people have been killed and more than 100 wounded across the country, as far away as the western city of Lviv, hundreds of miles from the war’s main theaters in eastern and southern Ukraine.