* Arab summit supports Saudi, UAE right to defend interests
* Iraq objects to final communique
* Emergency summits follow attacks on pumping station, tankers
* Tensions rising between Iran and United States
* Iran vows to counter any economic, military aggression (Adds communiques, Iraq objection to summit statement)
MECCA, Saudi Arabia, May 30 (Reuters) - Saudi Arabia's king told an emergency Arab summit on Thursday that decisive action was needed to stop Iranian "escalations" in the region following attacks on Gulf oil assets, as American officials said a U.S. military deployment had deterred Tehran.
A Gulf Arab statement and a separate communique issued after the wider summit both supported the right of Saudi Arabia and the United Arab Emirates to defend their interests after the attacks on oil pumping stations in the kingdom and tankers off the UAE.
But in a sign of regional tensions, Iraq, which has good ties with neighbouring Iran and Washington, said it objected to the Arab communique, which stated that any cooperation with Tehran should be based on "non-interference in other countries".
"The absence of a firm deterrent stance against Iranian behaviour is what led to the escalation we see today," King Salman told the two late night consecutive meetings.
The ruler of the world's top crude exporter said Shi'ite Iran's development of nuclear and missile capabilities and its threatening of world oil supplies posed a risk to regional and global security.
U.S. Secretary of State Mike Pompeo said on Thursday that the attacks on the four vessels near a major bunkering hub, just outside the Strait of Hormuz, were "efforts by Iranians to raise the price of crude oil around the world."
Riyadh accused Tehran of ordering the drone strikes, which were claimed by Yemen's Iran-aligned Houthi group. U.S. national security adviser John Bolton said on Thursday that evidence of Iran's being behind the tanker attacks would be presented to the U.N. Security Council as early as next week.
Tehran denies any involvement.
Iraqi President Barham Salih, asking the gathering to support his country's stability, said that rising tensions with Iran could spark a war if not managed well and voiced hope that Iran's security would not be targeted.
Both Riyadh and Abu Dhabi have said they do not want war.
"The kingdom is keen to preserve the stability and security of the region, to spare it the scourge of war and to realise peace and stability," King Salman said.
Tensions have risen between the United States and Iran after U.S. President Donald Trump a year ago withdrew Washington from a 2015 international nuclear deal with Iran, re-imposed sanctions and boosted its military presence in the Gulf.
Bolton has said that Iranian mines were "almost certainly" used in the tanker attacks. An Iranian official dismissed Bolton's remarks as "a ludicrous claim."
The Islamic Republic has said it would defend itself against any military or economic aggression. Iranian Vice President Eshaq Jahangiri has said Tehran was not allowed to pursue development of nuclear weapons as it was banned by Supreme Leader Ayatollah Ali Khamenei.
The final communique said regional stability required the establishment of an independent and sovereign Palestinian state along 1967 borders. In 1967 Israel captured Gaza, the West Bank and East Jerusalem in a war with Arab states.
U.S. special envoy for Iran, Brian Hook, said on Thursday that a repositioning of U.S. military assets in the region had succeeded in deterring Iran, but that the United States would respond with military force if its interests are targeted.
Last week the Pentagon announced the deployment of 900 additional troops to the region and extended the stay of 600 other service members, after speeding up deployment of an aircraft carrier strike group and sending bombers and additional Patriot missiles.
Egyptian President Abdel Fattah al-Sisi told the summit that this month's attacks provided an impetus to renew discussions on joint Arab defence mechanisms.
The United States and the UAE, which hosts a U.S. air base, on Wednesday activated a defence cooperation agreement signed earlier this year.
Gulf states have a joint defence force under the Gulf Cooperation Council (GCC), but the alliance has been fractured by a boycott imposed on Qatar by Saudi Arabia, the UAE, Bahrain and non-GCC Egypt since mid-2017.
The Gulf Arab communique, carried by Saudi state news agency SPA, said the six nations had discussed the GCC defence mechanism during their meeting.
Qatari premier Abdullah bin Nasser Al Thani, whose country hosts the largest U.S. military base in the region, attended the summits, the most senior Qatari official to visit the kingdom since the embargo.
(Reporting by Marwa Rashad and Aziz El Yaakoubi; Additional reporting by David Brunnstrom in Washington, Ali Abdelaty in Cairo, Guy Faulconbridge in London, Lisa Barrington and Sylvia Westall in Dubai, Eric Knecht in Doha and Babak Dehghanpisheh in Geneva; Writing by Ghaida Ghantous, William Maclean, Andrew Cawthorne; editing by Frances Kerry, Leslie Adler and Grant McCool)