The missile strike Sunday was one of the deadliest single attacks on Ukraine this year, as diplomatic efforts led by the U.S. have yielded few results.
U.S. special envoy Steve Witkoff met in St. Petersburg with his Russian counterpart, while Ukraine's NATO allies pledged an additional $23 billion to Kyiv's war effort.
The meeting in Istanbul followed initial talks in February after the war in Ukraine triggered the biggest confrontation between Moscow and the West since the depths of the Cold War.
Ksenia Karelina, a Russian American who lived in Los Angeles, spent over a year in prison after she donated to a charity that sends aid to Ukraine, a legal group said.
The Ukrainian president said he had instructed his Foreign Affairs Ministry to immediately contact Beijing and find out “how China is going to react to this.”
Ukrainian troops remain in neighboring Russian regions eight months after a cross-border incursion, though Russian forces recaptured much lost territory.