Despite this, the would-be host of the Trump-Putin summit said it could still happen.

Viktor Orban, Hungary’s prime minister who is a long-time ally of Trump’s and has warm relations with Putin, said that his ambassador in Washington was still working on the meeting.

“Preparations for the peace summit continue,” Orban wrote on Facebook. “The date is still uncertain. When the time comes, we will organize it.”

Russian Deputy Foreign Minister Sergei Ryabkov also told state media that preparations for the summit were continuing.

Though Trump has claimed victories in helping calm other global conflicts, Ukraine — a war he once said he could solve in 24 hours — has so far proved more difficult. He has variously sought to strong-arm Zelenskyy and Putin with few tangible results.

Ukraine and its supporters point to Putin’s repeated attacks on Ukrainian civilians as evidence that he is not interested in peace, and merely wants to use the negotiations to buy time for his military assault on his neighbor.

Tuesday night brought the latest barrage, more than 400 drones and 20-plus missiles, around 350 of which were shot down, Ukraine’s air force command said. In all, at least 13 people were killed over the past 24 hours, according to officials early Wednesday.

Among the targets was a kindergarten in the eastern city of Kharkiv, killing at least one person and injuring seven others, Zelenskyy said.

“There is no justification for a drone strike on a kindergarten, nor can there ever be,” he said in a post. “Clearly, Russia is growing more brazen. These strikes are Russia’s spit in the face to everyone who insists on a peaceful resolution.”

The Russian Defense Ministry said it had targeted sites supporting “the operation of Ukraine’s military-industrial complex” with “high-precision long-range weapons.”