Israeli Foreign Minister Tzipi Livni has cancelled plans to visit Qatar to attend an international conference.
Livni: No talks scheduled with Qatari officials
A spokesman said she decided not to go after learning Hamas members would represent the Palestinian government.
Hamas refuses to recognise Israel and its charter calls for the destruction of the Jewish state.
Qatar and Israel maintain low-level trade and diplomatic ties. Ms Livni would have been the most senior Israeli official to visit for 10 years.
The ministry said it had instead sent its deputy director for Middle East affairs, Yacov Hadas, to the conference.
Ms Livni had been invited to the sixth International Conference on New or Restored Democracies beginning in Doha on Sunday.
"We have learnt that members of Hamas will represent the Palestinians at the international conference in Qatar, and Ms Livni has therefore decided to cancel her visit there," spokesman Mark Regev told AFP news agency.
"Israel rejects all contacts with Hamas for as long as it does not respect the three preconditions set by the international community: it must give up violence and recognise Israel and the agreements signed by the Palestinians," he said.
The last high-profile Israeli visit to Qatar was by the then prime minister, Shimon Peres, in 1996.
Sunday's conference, which hopes to bring together top representatives from at least 27 states, is expected to focus on reform in the Arab world.
Freedom of speech and the participation of women in political life are also to be key issues.