Ukrainian President Volodymyr Zelensky has warned that his country may be heading into another winter of war, as diplomatic efforts involving Russia and the United States have yet to produce a decisive breakthrough.

The warning followed separate meetings in Moscow and Kyiv involving US envoys Steve Witkoff and Jared Kushner. The two officials first met Russian President Vladimir Putin before travelling by train to Kyiv, where they held several hours of closed-door discussions with Zelensky and Ukrainian officials.

While Witkoff described the engagements as “substantive” and said he was encouraged by the discussions, Zelensky struck a more cautious tone, saying the war appeared likely to continue into the winter. He stressed that any peace agreement must be durable and prevent Russia from launching another aggression against Ukraine.

A major concern for Kyiv is how to withstand another season of Russian attacks on its energy infrastructure. Zelensky said Ukraine would require additional air-defence and energy support, particularly as American Patriot interceptor stocks have been depleted by the United States’ recent military commitments.

The Ukrainian leader also said his country must strengthen its own ability to intercept ballistic missiles, while expressing hope that increased American production of air-defence systems next year would improve Ukraine’s access to the weapons.

Despite the diplomatic activity, fighting has continued. Ukraine said it struck an oil refinery, an airfield and two air-defence systems, while its Air Force reported that Russia launched 108 long-range drones and cruise missiles. Ukrainian forces said they intercepted 82 drones and six missiles, although several locations were still hit.

The latest diplomatic push is expected to continue with a meeting involving Ukrainian, European and American officials, while Zelensky has renewed his call for direct trilateral negotiations involving Ukraine, Russia and the United States. Russia, which still controls roughly one-fifth of Ukrainian territory, has continued to claim battlefield advances, but its ground forces have made only limited progress despite heavy losses.