The Hamas premier in Gaza has not been invited to this week's summit of the Non-Aligned Movement in Tehran, Iran said on Sunday, heading off a threatened boycott by the Palestinian president.

"Up to now, no official invitation from the Islamic Republic of Iran and the person of (President Mahmoud) Ahmadinejad has been sent to Hamas's popular prime minister (Ismail Haniya)," the Iranian spokesman for the summit said.

"Only (Palestinian president) Mahmud Abbas has been invited to the NAM summit," Mohammad Reza Forqani said in a statement quoted by the ISNA and Mehr news agencies.

Hamas said on Saturday that Haniya would take part in the summit in Tehran on Thursday and Friday, "in accordance with the invitation from Iranian President Mahmoud Ahmadinejad," according to a statement by his spokesman.

Abbas, whose internationally recognised Palestinian Authority is at odds with Gaza's Islamist Hamas rulers, responded with a warning through Palestinian foreign minister Riyad al-Malki that he would stay away from the summit if Haniya went.

Forqani's statement that Haniya had never been invited appeared an effort to spare Iran embarrassment over an Abbas boycott. Iran is a fierce supporter of the Palestinian cause and an arch-foe of Israel.

On Saturday, Iran's foreign ministry spokesman, Ramin Mehmanparast, told reporters that Iran has "the duty to invite all (NAM) members" and that Abbas would take part and "some special guests" had also been invited.

The NAM, born at the height of the Cold War as a grouping of nations that saw themselves as independent of both Washington and Moscow, counts 119 member states plus "Palestine" as members.

Other participating nations include Afghanistan, Armenia, Azerbaijan, Egypt, Ghana, India, Iraq, Kuwait, Pakistan, Sudan, Tajikistan, Turkmenistan and Zimbabwe.

Iran is presenting the summit as proof that it is not as isolated on the world stage as the United States has tried to portray.

On Sunday, a meeting of experts from NAM countries began a two-day meeting in Tehran to prepare for the summit. On Tuesday and Wednesday, foreign ministers from several of the countries are to develop that work ahead of the summit itself on Thursday and Friday.