DOHA - Iran went on a charm offensive in Qatar on Monday, hailing its debut presence at a summit of Gulf leaders as ushering in a new era of regional ties, but its Arab neighbours offered no immediate matching welcome.

In contrast to lengthy statements to reporters by Iranian President Mahmoud Ahmadinejad, U.S-allied Gulf Arab leaders were yet to react to Iran's proposals for greater cooperation on economic and security issues at the two-day summit.

Iranian officials deflected questions regarding Gulf input into defusing the crisis over Iran's nuclear ambitions.

"This era has changed and the time of threats has ended...Iran has chosen its path and from our point of view the nuclear issue has ended," Ahmadinejad told reporters, referring to the West's plans to impose further sanctions on Iran.

He spoke after the opening ceremony of the Gulf Cooperation Council's annual summit meeting in the Qatari capital Doha.

Ahmadinejad, who regularly rails against the United States, said of his trip to Qatar: "It seems a new chapter has been opened in the relations between the Persian Gulf States."

"Iran's definite policy is to promote broad cooperation with all countries particularly friendly neighbouring countries."

GCC members Saudi Arabia, Oman, the United Arab Emirates, Kuwait, Bahrain and Qatar share Western concerns about Iran's nuclear programme and some have maritime border disputes with the Islamic Republic.

A new U.S. intelligence report released on Monday said Iran halted its nuclear weapons programme in 2003 and it remained on hold, contradicting the Bush administration's earlier assertion that Tehran was intent on developing a bomb.

The report could hamper U.S. efforts to convince other world powers to agree on a third package of U.N. sanctions against Iran for defying demands to halt uranium enrichment activities.

Iran says it wants nuclear technology only for civilian purposes, such as electricity generation.

"SERIOUS THREATS"

In the summit's opening speech, Qatar's ruler Hamad bin Khalifa al-Thani said the meeting was taking place amid "serious threats" to the region's prosperity and security, without clarifying the threat.

Ahmadinejad did not mention Iran's nuclear plans in his speech at the opening ceremony, and Foreign Minister Manouchehr Mottaki gave little indication of Iranian measures to reassure Gulf neighbours about the nuclear standoff with the West.

No mention was made in Ahmadinejad's speech of a Saudi proposal last month for Gulf Arab states to supply Iran with enriched uranium in a bid to lessen tensions with the West.

Ahmadinejad instead called for increasing cooperation in economic and security fields, proposals which have been aired in the past but largely ignored by Gulf states.

In calling for increased security cooperation, he told the leaders of the Gulf states that any security problem in one country would spill over to neighbouring states.

"We welcome peace and complete security without outside influence," he said during the speech, repeatedly referring to the Gulf as Persian, not Arabian, as Arab states insist is the correct name.

"Any security problem that could happen in one country will have a negative effect on the security of all countries," he said in the speech.