Flights to Havana via Conakry in Guinea began 10 July 1962. After the United States government placed political pressure on Guinea, landing rights were denied after four flights, and the Tu-114 service had to be routed through Dakar, Senegal, instead. Further American pressure to isolate Cuba resulted in denial of landing rights after three flights, and the route was changed to Algiers, Algeria, instead. After three more flights, Algiers was also closed to the Tu-114. To overcome this, the Tu-114 was specially modified into the long-range Tu-114D variant, with seating reduced from 170 to 60, and 15 extra fuel tanks added. These aircraft refuelled at Olenya near Murmansk, in the far North of the Soviet Union, and then flew via the Barents Sea to Havana. Usually, this fuel load was enough, but in case of strong headwinds, an emergency refuelling stop in Nassau in The Bahamas was necessary; this was an American military field. All planes operating this route were converted back to normal specifications after the jet-powered Ilyushin Il-62 began flying the Moscow–Havana route.