Ukrainian President Volodymyr Zelensky has said he may not meet with Russian President Vladimir Putin again.

During a speech on Ukrainian television, Zelensky said negotiations are the only way to resolve the situation, but he and Putin may never meet. “Ukraine will demand that the Bucha massacre be tried as a war crime,” Zelensky was quoted as saying by Reuters.

The Ukrainian president also said at least 300 civilians had been killed in the town near Kiev, calling Russia’s execution of civilians there a genocide. A day earlier, it was reported that over 410 people had been killed. Russia, for its part, denies the allegations and considers the footage of the dead bodies in Bucha as false and Western propaganda.

On the other hand, Zelensky said that in other cities of Ukraine there may be similar massacres, with even larger numbers.