The United States delivered a sharp warning to the Kremlin at the UN Security Council on Monday, saying Russia’s window for improving its position in Ukraine is narrowing and urging Moscow to make a deal to end the war. “As President Trump made clear during the G7 Summit last week: Russia should make a deal. Time is not on Moscow’s side,” said Den Negri, the United States’ Deputy Permanent Representative to the United Nations.JOIN US ON TELEGRAMFollow our coverage of the war on the @Kyivpost_official. The remarks came as Washington sought to reinforce the G7 message on Russia, while UN officials warned of a sharp rise in civilian casualties from Moscow’s intensified attacks. Negri argued that Russia is paying an increasingly unsustainable price to maintain its war effort. “Russia is taking 40,000 casualties per month. Its economy is severely strained. Ukraine is innovating quickly,” he said. “Diplomacy and negotiation, not more bloodshed, are the only answer. Nothing else will stop this senseless killing. This war has gone on for far too long, and it must end.” Deadliest month for civilians since 2022 The Security Council session was convened to address Russia’s latest wave of attacks on Ukraine, including strikes that damaged civilian infrastructure and cultural heritage sites. UN officials said May was the deadliest month for civilians in Ukraine since April 2022, as Russia intensified missile and drone attacks across the country.