The six-nation Gulf Cooperation Council (GCC) confirmed on Sunday that it had invited Iranian President Mahmoud Ahmadinejad to attend its summit this week, the first such invitation to the Islamic Republic.
"President Ahmadinejad will be the guest of the summit," GCC secretary general Abdulrahman al-Atiyah told reporters ahead of the two-day summit which starts on Monday.
"This is the first time that the Islamic Republic of Iran gets invited," to a GCC summit, he said, but gave no details on how long Ahmadinejad would stay in the Qatari capital which is hosting the meeting.
Ahmadinejad's senior advisor Mojtaba Samareh Hashemi said last Thursday that the outspoken president would be at the meeting, which will be attended by the heads of state from Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.
Iran has on occasion had rocky ties with GCC member states, most notably in the 1980s when regional heavyweight Saudi Arabia backed Saddam Hussein's Iraq in its eight-year war against Iran.
But Iran has been seeking to improve ties as it faces increasing international isolation over its nuclear programme, and senior officials have made regular trips to neighbouring countries.
Meanwhile, Iran's Foreign Ministry confirmed on Sunday that Iranian President Mahmoud Ahmadinejad will attend this week's summit of six US-allied Gulf Arab states in Qatar, saying it could help boost regional cooperation.
It was the first time an Iranian president had been invited to a Gulf Cooperation Council (GCC) summit, Foreign Ministry spokesman Mohammad Ali Hosseini said.
Hosseini said Ahmadinejad had been invited to the December 3-4 meeting in Doha by Qatar Emir Hamad bin Khalifa al-Thani, but the spokesman did not specify in what capacity the president would be there or for how long.
He said the presence of Ahmadinejad, who often rails against the United States, at the summit could be an "important step" in promoting cooperation in the Gulf, the world's top oil exporting region.
The Islamic Republic regularly calls for a security cooperation pact with Gulf Arab states as the best way of securing the region and ridding it of U.S. forces, a plan Gulf Arabs have ignored.
The United Arab Emirates has a long-running border dispute with Iran over the sovereignty of three Gulf islands.
The United States accuses Iran of seeking to build nuclear bombs, a charge Tehran denies. Washington says it is committed to diplomacy to resolve the stand-off but has not ruled out military action if that were to fail.