Gulf Arab leaders on Tuesday endorsed Saudi King Abdullah's call to form a 'single entity' after hinting at Iranian threats, and demanded Syria immediately implement an Arab peace plan to defuse months of violence over anti-government protests.

The foreign minister of Saudi Arabia said, after the six-member Gulf Cooperation Council (GCC) summit meeting, that Syria must embrace all of the Arab league plan it has signed, which calls for pulling troops from population centres, releasing prisoners and dialogue with opposition forces.

'If the intentions are pure, these steps must be taken immediately,' Saudi Foreign Minister Prince Saud Al-Faisal said in response to a question about Syria's signing of the plan from the Arab League, which has also imposed sanctions on Damascus.     

His remarks came as the six-member GCC concluded its highest-level meeting since a wave of protests swept the Arab world earlier this year, and pledged closer military and security integration in a final statement read out on Saudi state television.     

But the statement made no specific reference to non-Arab Iran, which Gulf leaders have accused of fomenting unrest in Bahrain.

Gulf leaders agreed on '...adopting King Abdullah's suggestion of moving from cooporation to unity that would support our people overcome the challenges faced by the GCC,' the statement said.

King Abdullah on Monday said the security of Saudi Arabia and its Arab neighbours was being targeted, in an apparent reference to regional rival Iran, and called on Gulf Arab states to 'move beyond the stage of cooperation and into the stage of unity in a single entity'.

He did not expand on the remarks, which drew applause from the hall where officials of GCC member states were sitting, but analysts said they were probably aimed at a perceived threat from Iran and the Arab uprisings.

The GCC members concluded their two-day meeting with a pledge to study and report back on the idea by March, without specifying any concrete steps that might be taken.

Analysts and officials said the idea of greater union in the GCC, which has seen little progress toward that goal expressed in its 1981 founding charter, had been discussed informally among members given concerns about the regional situation.

Proposals for a customs union, single currency and shared military command have not been realised, although the countries did form a small joint armed force that sent troops to Bahrain in February at the request of the kingdom.

Earlier this year, the Gulf Arab states said Morocco and Jordan, the two other Arab monarchies, might join the group. However, there has been no further announcement. - Reuters