Maria Zakharova, a Russian foreign ministry spokesman, accused Ukraine of resorting to terrorism, the TASS state news agency reported.
Russia accused Kyiv’s forces last month of killing 11 people, including four children, in an attack on a holiday camp in a Russian-held part of Ukraine’s Zaporizhzhia region.
The conflict has led to a growing number of civilian deaths this year, the UN has reported, as the four and a half-year war grinds on with no sign of a peace deal.
It comes as Ukraine’s former top military commander, now ambassador to Britain, said on Monday that there was no prospect of the country joining Nato.
Valery Zaluzhnyi, quoted by media outlet Evropeiska Pravda, told a meeting of Ukrainian ambassadors that Ukraine in no way met the military standards needed to join the alliance.
“I know Nato really well. For about 12 years, I personally worked on making sure we met Nato standards, and every year I heard tales about how we would join Nato any day now,” he was quoted as saying.
“Unfortunately, we will never actually join.”
Mr Zaluzhnyi said it was “impossible with the level of development that the Armed Forces of Ukraine have … to join an organisation guided by World War II doctrines”.
Ukraine has enshrined in its constitution a strategic goal of membership of Nato and the European Union. It has, however, acknowledged that currently it would not be welcomed into Nato by all its members.
Mr Zaluzhnyi was dismissed as Ukraine’s top commander in 2024 over differences with Mr Zelensky on the war with Russia.