KYIV -- Ukrainian President Volodymyr Zelenskyy called for resumption of trilateral negotiations between the United States and Russia as US envoys Steve Witkoff and Jared Kushner concluded talks in Kyiv and Moscow, including with Russian leader Vladimir Putin, as part of efforts to end the conflict, now in its fifth year.Both Zelenskyy and Witkoff described the September 6 talks as "substantial," with the Ukrainian president telling reporters that, among other things, the sides discussed security and economic guarantees for Kyiv, supplies of urgently needed air-defense missiles, as well as a support package for Ukraine, as another wartime winter looms.At the same time, Witkoff stressed that the United States was seeking a diplomatic resolution to the conflict rather than a kinetic one, while Kushner supported the idea of renewing trilateral negotiations between Kyiv, Moscow, and Washington."It's going to take both sides to make some compromises and narrow the issues between them and we think we have the ingredients to get to that place," Witkoff said. "It is very difficult but we are committed."Separately, as the Kyiv talks were unfolding, Zelenskyy wrote on his Telegram page that representatives of Britain, France, and Germany had also joined the discussions.Zelenskyy offered some guarded remarks following the talks, suggesting no immediate breakthrough."We had three rounds of talks today. All of them were very substantive," he wrote on social media as Ukrainian officials told reporters that Zelenskyy, Witkoff, and Kushner met again following the formal sessions."We hope we will have the opportunity to reach an agreement with our American partners, and we hope for the support of our European partners.""If the war continues in the winter, we are very much counting on the winter [aid] package, which I discussed in detail with Steve, Jared, and our European partners today."Zelenskyy said Ukraine is "counting on support for both air defense and energy, and for a serious volume and possibilities of using American [liquid natural gas]."A year ago, Ukraine suffered through a brutal winter as Russia targeted the country's energy infrastructure, leaving hundreds of thousands of residents without heating.The Ukrainian railway said in the early hours of September 7 that the American envoys departed Kyiv by "special train," likely headed to Poland for a flight back to the United States.