Russia on Thursday struck the central Ukrainian city hundreds of kilometres from the frontlines with high-precision Kalibr sea-based missiles.

Ukraine said 23 people, including children, were killed in the attack.

Moscow insists it targeted the Ukrainian military.

"At the time of the strike, a meeting of the command of the Ukrainian Air Force with representatives of foreign arms suppliers was held," the Russian defence ministry said.

The meeting focused on supplies of jets and weapons as well as repair of Ukraine's aircraft, the ministry said in a statement.

"As a result of the strike, the participants of the meeting were destroyed."

Ukrainian President Volodymyr Zelensky said the toll in Vinnytsia was likely to rise. Dozens are still missing and many hospitalised in critical condition.