Hamas said on Thursday its presentation of a new Palestinian government for parliamentary approval next week would force the group to miss a two-day Arab summit due to begin on Tuesday.
"Hamas will not participate in the Arab Summit in Sudan because some Palestinian parties have delayed the measures related to the presentation of a Hamas government to parliament," Mohammad Nazzal, a Hamas leader, told Reuters by telephone from Bahrain.
Hamas, winner of the Palestinian parliamentary election in January, is to present its cabinet to the legislature on Monday. The parliament would then debate the line-up and later hold a vote of confidence.
Nazzal said the parliamentary proceedings could take days.
"It means ... that no one from the Hamas government will attend the summit," he said.
In a report on Sunday, Yemen's state news agency said Hamas expected Arab states that have pledged financial aid to a Hamas-led administration to specify the amount of funds they will give when they meet in Khartoum next week. Israel and the United States have called on other nations to boycott Hamas.
Nazzal accused Palestinian President Mahmoud Abbas, whose Fatah faction was crushed in the January 25 poll, of effectively blocking Hamas's participation by delaying the moves to approve the government.