The leaders of Russia and Ukraine on Wednesday lashed out, accusing each other of sabotaging peace prospects amid escalating attacks and highlighting the deep animosity that is keeping the sides as far apart as ever.

Speaking at a meeting with high-ranking government officials in Russia, President Vladimir V. Putin did not mention Ukraine’s audacious recent drone strikes on Russian strategic bombers, but concentrated instead on apparent attacks that derailed two Russian trains on Sunday, killing seven people.

After hearing a report from Russia’s top investigator, who said that the railway attacks had been committed by Ukrainian special services, Mr. Putin accused Kyiv’s leadership of ordering them to disrupt the second round of the Russian-Ukrainian talks that took place on Monday in Istanbul.

“They are asking for a summit meeting,” Mr. Putin said, referring to Ukraine’s request for an in-person meeting between him and President Volodymyr Zelensky.

“But how can such meetings be held in these conditions?” Mr. Putin asked. “How can we negotiate with those who rely on terror?”

President Trump said Wednesday that he had spoken with Mr. Putin for the first time since the weekend. In a Truth Social post, referring to the drone strikes against bombers, Mr. Trump said, “President Putin did say, and very strongly, that he will have to respond to the recent attack on the airfields.”