Russia’s defence minister held rare telephone talks with his US counterpart on Friday, after pro-Kremlin officials said they were turning Ukraine’s southern city of Kherson into a “fortress” as Kyiv’s forces advance. Few details emerged of the conversation between Russia’s Sergei Shoigu and the US Defence secretary, Lloyd Austin, but both sides confirmed they had discussed Ukraine. “Topical issues of international security – including the situation in Ukraine – were discussed,” Russia’s defence ministry said. The Pentagon declined to offer specifics beyond saying that Austin, who initiated the conversation, emphasised a need for lines of communication amid the war in Ukraine. “Secretary Austin emphasised the importance of maintaining lines of communication amid the ongoing war against Ukraine,” A US military spokesperson said. Russian news agency Tass quoted Vienna-based Russian diplomat Konstantin Gavrilov as telling Russian television: “Misunderstandings must be cleared up so that there are no accidents … these are always important contacts, and it’s important the Americans were the first to go for it.” Gavrilov, a senior security negotiator, also said that in the wake of the call Moscow expected clarification about nuclear deterrence exercises that Nato is carrying out, TASS added. A Pentagon spokesperson said Friday offered the best opportunity for the two sides to speak, without explaining why that was the case. She did not say whether any additional talks were scheduled between the two. It was only the second call between the ministers since Moscow invaded Ukraine in February. In May, Austin had urged Moscow to implement an “immediate ceasefire”. At the time, Russia’s invading force had been beaten back from the capital of Kyiv but were making steady gains in the eastern Donbas and Kharkiv regions and had consolidated their position in the south. Six months on, however, Ukraine’s forces have pushed back. Kyiv’s forces in recent weeks – aided by western weapons – have been advancing along the west bank of the Dnieper River towards the region’s main city Kherson. It was the first major city to fall to Moscow’s troops and retaking it would be a significant prize in Ukraine’s counter-offensive.