Officials in Kyiv and Moscow were, as part of the mediation process, compiling lists of children moved to Russia since its full-scale invasion in February 2022.
Russia's defense ministry said it had struck Odesa, where the Ukrainian navy has its headquarters, and Mykolaiv, near Ukraine's Black Sea coast.
"The hardest thing is that her parents died, dad and mum," Russia's Belgorod governor said.
Russian forces claim to have shot down nine Ukrainian drones over the Crimean port of Sevastopol on Sunday.
There was no immediate comment from Ukraine on the Russian allegation.
It is on a route used by the Russian military to move between Crimea and other parts of Ukraine under its control.
Kyiv says it wants to reclaim all of its territory, including the Crimean peninsula
At the time of the attack, a US RQ-4 Global Hawk unmanned surveillance aircraft was in the central area of the Black Sea, the defense ministry said.
The appeal for Palestinian terrorist Walid Daqqah’s early release was based on his worsening health condition, which supporters said required consistent treatment.
Russia shows no sign of abandoning Crimea, home to its Black Sea fleet, and has used the peninsula as a platform to launch missile strikes on Ukrainian targets.