Russian forces have driven the Ukrainian army out of the biggest town in Russia’s Kursk border region, officials claimed Thursday, as President Trump’s senior envoy arrived in Moscow to discuss a U.S.-proposed 30-day ceasefire in the three-year war that Ukraine has endorsed. The Russian Defense Ministry’s claim that forces had recaptured the town of Sudzha, made hours after President Vladimir Putin made a first visit to commanders in Kursk, wearing military fatigues and promising the full recapture of the region, could not be independently verified.Ukrainian officials did not immediately comment on the claim, but it came as a U.S. official confirmed to CBS News that Russian troops had made “significant gains” in Kursk over the past week. Russia has been maneuvering to surround the Ukrainian forces who launched a surprise incursion into Kursk months ago, and they have succeeded in doing so to the extent that the Ukrainians will likely soon have to decide whether to withdraw back into Ukraine, or be cut off from their supply lines, the American official told CBS News.