Two southeast Ukrainian regions seized by Russian troops have switched to Russian area codes, state-owned mediareported Friday, citing officials.New telecom operators are already working [in Kherson and Zaporizhzhia regions], Oleg Kryuchkov, an adviser to the head of the annexed region of Crime told RIA Novosti news agency.A RIA Novosti correspondent based in the Crimean city of Simferopol said they were able to reach a Kherson phone number using Russias +7 area code.The Kremlin has installed pro-Moscow military-civilian administrations in areas of southeastern Ukraine that were seized by Russian troops, prompting speculation that Russia is looking to formally annex the region.SIM cards with +7 phone numbers are already on sale in Kherson and Zaporizhzhia regions, according to Kryuchkov.The SIM cards are serviced by Russias K-Telecom carrier network, which operates under the Win Mobile brand in Crimea, Russias Vedomosti business daily reported Friday, citing an unnamed telecom industry source.The area code switch from Ukraines +380 to +7 marks the latest Russification of the occupied regions where Russia has already introduced the ruble and Russian internet services.Several Russian and Moscow-installed local officials have signaled in recent weeks that occupied territories in southern and eastern Ukraine will be absorbed by Russia.President Vladimir Putin, who had denied plans to occupy Ukraine when he ordered troops into Russias pro-Western neighbor, signed a decree this week fast-tracking Russian citizenship for residents of Kherson and Zaporizhzhia.