At least 41 people were killed and 180 others injured in a Russian strike on a military academy in central Ukraine's Poltava on Tuesday, President Volodymyr Zelenskyy confirmed.

"More than 180 people were injured. Unfortunately, there are many dead. As of now, 41 people have been reported dead," Zelenskyy said.

Two ballistic missiles "hit the territory of an educational institution and a neighboring hospital," he added, in one of the deadliest single strikes of the two-year war.

Zelenskyy said in a video that Russian forces struck with missiles, damaging a building of the Military Institute of Communications.

He added that he had ordered a full and prompt investigation into the circumstances of the attack.

"The Russian scum will definitely be held accountable for this strike," Zelenskyy said on the Telegram messaging app.

He repeated his calls for more Western air defenses and urged allies to allow their long-range weapons to be used for strikes deeper into Russian territory in order to protect Ukraine.

"We keep telling everyone in the world who has the power to stop this terror: air defense systems and missiles are needed in Ukraine, not in a warehouse somewhere," Zelenskyy said.

"Long-range strikes that can protect us from Russian terror are needed now, not sometime later. Unfortunately, every day of delay means loss of life," he added.