National Security Advisor Jake Sullivan has held undisclosed talks with top Russian officials in hopes of reducing the risk the war in Ukraine spills over or escalates into a nuclear conflict, the Wall Street Journal reported on Sunday. The newspaper cited US and allied officials as saying that Sullivan, PresidentJoe Biden’s top aide on national security, held confidential conversations in recent months with Kremlin aide Yuri Ushakov and Russian Security Council secretary Nikolai Patrushev, Sullivan’s counterpart, that were not disclosed publicly. The White House declined to comment on the rep…