GAZA, Feb 26 (Reuters) - Hamas's prime minister-designate Ismail Haniyeh on Sunday denied he had suggested the Palestinian Islamist group might one day recognise Israel, saying there was only a possibility of achieving a long-term truce. Hamas chose Haniyeh, a 43-year-old Gazan viewed by many Palestinians as a pragmatist, as the new prime minister after its election victory on Jan. 25. The militant Islamist group hopes to form a Palestinian government within two weeks. The Washington Post newspaper, on its Web site, quoted Haniyeh as saying in an interview: "If Israel declares that it will give the Palestinian people a...