Ukrainian President Volodymyr Zelensky attends a press conference devoted to his two years in office in Kiev, Ukraine, May 20, 2021.File photo:Xinhua

Ukrainian President Volodymyr Zelensky said Thursday that Kiev decides to sever diplomatic relations with Moscow after Russia launched military operations in Donbass, the government-run Ukrinform news agency reported.

"Ukraine is defending itself," Zelensky said in a televised address. He added that more than 40 Ukrainian soldiers and around 10 civilians were killed in the conflict.

Earlier Thursday, Russian President Vladimir Putin authorized the "special military operation," and Ukraine confirmed that military installations across the country were under attack.