The six Gulf monarchies meeting in Doha on Tuesday condemned as "provocative" a visit by Iranian President Mahmoud Ahmadinejad to an island claimed by both Abu Dhabi and Tehran.
The members of the Gulf Cooperation Council "strongly condemn the Iranian president's visit to Abu Musa which is a provocative act and a flagrant violation of the sovereignty of the United Arab Emirates over its three islands," they said in a joint statement.
The visit, last week, "contradicts good neighbourly policies," they added.
The GCC also demanded Iran "end its occupation of these islands and respond to calls by the UAE to find a peaceful and just solution through negotiations or by resorting to the international court."
The group further pledged their "full support to the UAE in all actions it takes to regain its rights and sovereignty over its islands."
Foreign ministers of the GCC -- grouping the UAE, Saudi Arabia, Qatar, Bahrain, Kuwait and Oman -- met at a special meeting in Doha Tuesday at the request of the UAE.
The UAE has summoned Iran's ambassador to Abu Dhabi to denounce Ahmadinejad's visit to Abu Musa, one of the three disputed islands that include Lesser Tunb and Greater Tunb.
Emirati Foreign Minister Sheikh Abdullah bin Zayed Al-Nahayan warned on Monday that if left unresolved, the issue "could jeopardise international security and peace."
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This was followed by a warning from Ahmadinejad who said Tuesday that Iran will respond with force to any threats to its territorial integrity.
"The armed forces and the army will inflict heavy regret and shame in case of any aggression against Iranian lands and interests," Ahmadinejad said, adding that Iran "is ready to protect its existence and sovereignty."
Abu Dhabi has also recalled its ambassador to Tehran and lodged a protest with the United Nations over Ahmadinejad's visit, stressing that the territorial dispute should be resolved in talks or at the International Court of Justice.
On Sunday, Sheikh Abdullah met ambassadors representing UN Security Council member states in Abu Dhabi to convey the "UAE's condemnation of this provocative visit," UAE's official news agency, WAM, said.
Tehran has insisted that Ahmadinejad's trip, during which he said historical documents proved "the Persian Gulf is Persian," was a purely "domestic issue."
Both Iran and the UAE claim territorial sovereignty over the three islands in the southern Gulf.
Iran, then under the rule of the Western-backed shah, gained control in 1971 of the islands as Britain granted independence to its Gulf protectorates and withdrew its forces.
Abu Musa, the only inhabited island of the three, was placed under joint administration in a deal with Sharjah, now part of the UAE.
Abu Dhabi says the Iranians have since taken control of the entire island which controls access to the oil-rich Gulf and have built an airport and military base there.