Ukraine's air force reported a major Russian attack on Monday night and into Tuesday morning -- the largest overnight barrage for weeks, coming while Ukrainian President Volodymyr Zelenskyy met with President Donald Trump and a delegation of European leaders in Washington. The air force said Russia launched 270 drones and 10 missiles into Ukraine, of which 30 drones and six missiles were intercepted or suppressed. The air force reported the impacts of 40 drones and four missiles across 16 locations, with debris reportedly falling in three locations. Ukraine's Energy Ministry said energy infrastructure in the central Poltava region was a focus of the strikes. "As a result of the attack, large-scale fires broke out," the ministry said in a statement. Oil refining and gas facilities were attacked, the statement said, describing the strikes as the latest in a campaign of "systematic terrorist attacks against Ukraine's energy infrastructure, which is a direct violation of international humanitarian law." Monday night's attack was the largest attack since Russia launched 309 drones and eight missiles into Ukraine on July 31, according to the daily figures published by the Ukrainian air force and analyzed by ABC News. Russia's Defense Ministry, meanwhile, said its forces shot down 23 Ukrainian drones overnight into Tuesday morning. Thirteen of the craft were downed over the Volgograd region, the ministry said. Regional Gov. Andrey Bocharov said on Telegram that falling debris set fires at an oil refinery and on the roof of a hospital building, though added there were no casualties. The overnight exchanges bookended a day of high-level talks in Washington. Trump, Zelenskyy and a host of European leaders met in the capital on Monday to discuss a possible roadmap to end Russia's full-scale invasion, which began in February 2022. Zelenskyy on Tuesday described the meeting as "truly a significant step toward ending the war." Monday's summit followed a meeting between Trump and Russian President Vladimir Putin in Alaska on Friday, during which Putin refused an immediate ceasefire and demanded that Ukraine cede the entirety of its eastern Donetsk region in exchange for an end to the fighting, two sources told ABC News. Ahead of Monday's meetings, Trump appeared to be pressuring Zelenskyy into making a deal. "President Zelenskyy of Ukraine can end the war with Russia almost immediately, if he wants to, or he can continue to fight," Trump wrote on social media on Sunday. The president also said Ukraine would not be allowed to join NATO and would not be able to regain Crimea -- occupied by Russia in 2014. Such remarks raised concerns of another fractious Oval Office meeting, akin to Zelenskyy's February visit when the Ukrainian leader was publicly lambasted by Trump and Vice President JD Vance for his alleged ingratitude for American wartime support. MORE: Key takeaways from Trump and Zelenskyy's meeting, pivotal talks with European leaders But Monday's meetings were cordial, though the parties still appeared to be some way apart on key issues. Trump, Zelenskyy and European leaders all confirmed their support for a direct bilateral meeting between Zelenskyy and Putin -- a proposal the Russian president has repeatedly dodged. Such a meeting would be followed by a trilateral meeting involving Trump, the president said. Zelenskyy said Ukraine is "ready" for a trilateral discussion. Trump remarked, "I think it's going to be when, not if." Later, Trump posted to social meda saying he had spoken by phone with Putin "and began the arrangements for a meeting, at a location to be determined, between President Putin and President Zelenskyy." The Kremlin is yet to explicitly confirm Putin's readiness to attend such a meeting. Yuri Ushakov, a top Kremlin aide, said in a statement that Trump and Putin "expressed their support for the continuation of direct negotiations between the Russian and Ukrainian delegations." "In this regard, in particular, the idea was discussed that the level of representatives from the Ukrainian and Russian sides should be increased," Ushakov said. "This refers to the representatives who participate in the aforementioned direct negotiations." On the question of security guarantees for Ukraine, Trump said during his meeting with Zelenskyy, "We're going to be discussing it today, but we will give them very good protection, very good security." The president later confirmed that Putin would accept security guarantees for Ukraine, though Russian officials on Monday said that the presence of NATO troops in the country would be unacceptable. Zelenskyy and his European partners again stressed their desire for a full ceasefire, only after which peace negotiations could take place. Trump has repeatedly demanded a ceasefire since returning to office in January, but appeared to drop the idea after last week's meeting with Putin. "I don't think you need a ceasefire," Trump told Zelenskyy in the Oval Office on Monday. "I know that it might be good to have, but I can also understand strategically, like, well, you know, one country or the other wouldn't want it." MORE: Trump says Zelenskyy can end Russia war 'almost immediately' before White House meet Trump added that he likes "the concept of a ceasefire for one reason, because you'd stop killing people immediately." Zelenskyy expressed his gratitude to Trump for hosting the meeting, and wrote on Telegram afterwards thanking the White House for "the important signal from the USA regarding readiness to support and be part of" post-war security guarantees. "The leaders personally came to support Ukraine and discuss everything that will bring us closer to real peace, a reliable security architecture that will protect Ukraine and all of Europe," Zelenskyy wrote. Post-meeting comments from European leaders, though, hinted at unresolved obstacles to peace. "You have an American president, European presidents and a Ukrainian president all wanting peace," French President Emmanuel Macron said. "For my part, I have the greatest doubts about the reality of a desire for peace on the part of the Russian president, because as long as he thinks he can win through war, he will do so," Macron added. "His ultimate objective is to take as much territory as possible, to weaken Ukraine and to have a Ukraine that is not viable alone or is within the Russian fold." German Chancellor Friedrich Merz said that the thorny issue of Ukrainian territorial concessions was not discussed. "The Russian demand that Kyiv give up the free parts of Donbas is, to put it in perspective, equivalent to the U.S. having to give up Florida," he said. "A sovereign state cannot simply decide something like that. It is a decision that Ukraine must make itself in the course of negotiations," Merz added. MORE: Ukrainian soldiers focus on daily battles as Trump and Putin prepare to meet ABC News' Alexandra Hutzler, Will Gretsky and Tanya Stukalova contributed to this report.
