ANKARA — The Kremlin confirmed for the first time on Friday that Russia remains in contact with Turkey over the fate of Ankara’s S-400 air-defense systems amid reports that they could be transferred to a Gulf country.Details: The issue has gained urgency after US President Donald Trump announced on Tuesday that the United States would lift sanctions imposed on Ankara over its purchase of the S-400s. Under US law, Turkey must no longer possess the Russian systems for the arms-sale sanctions to be removed.Earlier Friday, Abdulkadir Selvi, a Turkish journalist with close ties to the government, reported in Hurriyet that Ankara was considering selling the S-400s to the United Arab Emirates or Qatar.Asked whether Ankara had sought Moscow's consent for a potential transfer of the S-400s, Kremlin spokesperson Dmitry Peskov did not answer directly, saying only that the matter was "an extremely sensitive issue.""We have been in contact with the Turkish side on this matter, and we will continue our contacts with the Turkish side on this issue," RIA Novosti quoted Peskov as telling reporters, in first such statement by the Russian side. Background: Turkey became the first NATO member targeted under the Countering America’s Adversaries Through Sanctions Act in 2020 after receiving the first batch of Russia’s S-400 surface-to-air missile system in 2019.As part of the US response, Ankara was blocked from acquiring F-35 fighter jets and removed from the international consortium that manufactures them.Turkey was seeking a solution to the issue during the NATO summit held in Ankara earlier this week. Trump’s announcement raised hopes, but his administration still needs Congress on board for the sanctions to be removed.A bipartisan congressional delegation that visited Turkey on the sidelines of the summit earlier this week suggested there had been some progress in talks aimed at resolving the long-running dispute, but warned that lawmakers still lacked sufficient details about the proposals under discussion.Rep. Mike Turner, who joined the briefing from Washington, said the details shared with Congress on Turkey’s S-400 system and its potential return to the F-35 program “appear to be promising.”Sen. Jeanne Shaheen, the top Democrat on the Senate Foreign Relations Committee, struck a more cautious note, saying that lawmakers still had “questions to answer” about what was being proposed. Why it matters: Peskov’s remarks on Friday marked the first confirmation by Russia of discussions between Ankara and Moscow over Turkey’s efforts to resolve the S-400 dispute.Al-Monitor has reached out to the Turkish Foreign Ministry for comment. Speaking later on Friday, Turkish Foreign Minister Hakan Fidan said Turkey is taking steps to resolve the issue without further elaborating. “We are also taking the necessary steps to resolve this issue,” Fidan told Turkey’s public broadcaster TRT. “Hopefully, we will reach a conclusion soon. I don’t think there will be any problem with that.”While the details of the 2017 Turkey-Russia agreement for the purchase of the missile systems remain unknown, the deal likely includes restrictions on where the systems could end up. Any potential Turkish sale or transfer of the systems to a third country would therefore likely require Russia’s approval.Fidan traveled to Moscow in June to meet Russian President Vladimir Putin and his Russian counterpart, Sergey Lavrov, just weeks before the NATO summit.