A Hamas official says Gaza's prime minister has dropped plans to attend this week's Non-Aligned Movement summit in Tehran.

The prospect of Prime Minister Ismail Haniyeh, of Hamas, attending the summit elicited an angry response from the rival Palestinian government in the West Bank. Its foreign minister, Riad Malki, warned that Palestinian Authority President Mahmoud Abbas would pull out of the summit should Haniyeh attend, and urged other nations to do the same.

The spat is the latest chapter in the rivalry between Hamas, which runs Gaza, and Abbas, who administers parts of the West Bank. Hamas seized Gaza from Abbas in 2007.

Haniyeh's office said earlier he was invited by Iran's president. Iran denied that.

After opening the summit of 120 developing nations on Sunday, Tehran denied media reports that it had invited Haniyeh. "From Palestine, only Mahmoud Abbas, the president of the Palestinian Authority, has been invited to Tehran for participation in this summit, and an official invitation has not been sent to any other individual," the semi-official Iranian news agency Mehr quoted Iran's Foreign Ministry spokesman Ramin Mehmanparast as saying.

Gaza government spokesman Taher Nunu said Sunday that Haniyeh decided not to travel.

On Saturday, Palestinian Prime Minister Salam Fayyad called on Haniyeh not to attend the summit, saying that the fact that he was invited reinforces the rift in the Palestinian people.

Fayyad described the invitation to Ismail Haniyeh as "a stab in the back of the Palestinian national project." In a statement, Fayyad said, "The Palestinian Liberation Organization is the sole representative of all the Palestinian people."

In response, Haniyeh spokesman Mohammed Awad published a statement saying that Haniyeh had no intention of responding to Fayyad.

Iranian Foreign Ministry spokesperson Rahmin Mehmanparast said Haniyeh was invited as a "special guest."

"At a time when [Foreign Minister Avigdor] Lieberman is waging an aggressive political campaign, the invitation to Haniyeh to attend the NAM summit indicates that Tehran has joined the hostile Israeli chorus," the Palestine Liberation Organization executive committee said in a statement.

Iran hopes to earn diplomatic kudos by hosting a summit of the Non-Aligned Movement from August 29-31 at a time when the West is seeking to cripple its economy and isolate it diplomatically over its disputed nuclear program. UN Secretary-General Ban Ki-moon has already said he will attend, defying calls from the United States and Israel to boycott the event.