The latest development comes after more lethal strikes hit Ukraine overnight, when Russian forces killed a 6-year-old girl in Kherson, officials said. 

The Russian Defense Ministry boasted of footage showing how they were relentlessly pounding Huliaipole with Grad rockets. At least six people were injured in a Russian drone attack on Odesa, which damaged the city's energy infrastructure, East2West news agency reported. Six more people were wounded from a Russian strike on Kryvyi Rih, the hometown of President Volodymyr Zelenskyy. But Ukrainian drones attacked Nevinnomyssk Azot, a key supplier of explosives and rocket fuel components.

Former Russian President and Security Council Deputy Chair Dmitry Medvedev warned that if the European Union uses frozen Russian state assets to provide financial support to Ukraine, Moscow could treat the move as a justification for war, help fund Ukraine’s budget and military needs. European Commission President Ursula von der Leyen said this week that Europe intends to ensure Ukraine "has the means" to defend itself, proposing support totaling about €90 billion, about $105.1 billion, over the next two years.

"We are increasing the cost of Russia’s war of aggression," von der Leyen said. She added that raising pressure on Moscow should help bring Putin to negotiations, even as Russia signals it is not ready to compromise.

Ukrainian President Volodymyr Zelenskyy responded publicly to the diplomatic momentum, writing on X that Ukraine is preparing additional meetings with American envoys. "Ukraine was heard, and Ukraine was listened to. And that matters," Zelenskyy wrote. "A dignified peace is only possible if Ukraine’s interests are taken into account."

He added that any peace effort must combine diplomacy with continued pressure on Moscow. "Everything depends on this combination — constructive diplomacy plus pressure on the aggressor."

Russia, meanwhile, has continued military operations across Ukraine, according to Associated Press reporting, as both sides prepare for additional negotiations in the United States.

Putin’s rejection of the plan and Medvedev’s warnings to Europe highlight widening diplomatic and military pressure points just as international efforts intensify to find an exit path from the nearly three-year war.

The Associated Press and Reuters contributed to this report.