"Repeating baseless claims will not have any influence on existing realities. The three Iranian islands have been and will remain an integral part of the Islamic Republic of Iran's territory," Iran's foreign ministry spokesman Ramin Mehmanparast said in a statement.
Iran's reassertion of sovereignty over the islands of Abu Musa, Greater Tunb and Lesser Tunb, which lie in the strategic Strait of Hormuz entrance to the Gulf, was a blunt rejection of UAE appeals to open dialogue on the issue.
UAE President Sheikh Khalifa bin Zayed al-Nahayan on Sunday renewed the call for Iran to settle the dispute "dialogue and accept international arbitration."
Tehran seized the islands in 1971, when colonial-era Britain withdrew from that part of the Gulf. It maintains the islands are a historic part of its territory and stations military forces on the largest of them.
The UAE claims ownership of the islands under an agreement signed with Britain, and has support from other Gulf Arab states and its ally the United States.