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The Obama administration has quietly drawn up plans to provide a key Persian Gulf ally with thousands of advanced "bunker-buster" bombs and other munitions, part of a stepped-up U.S. effort to build a regional coalition to counter Iran.

The proposed sale to the United Arab Emirates would vastly expand the existing capabilities of the country's air force to target fixed structures, which could include bunkers and tunnels-the kind of installations where Iran is believed to be developing weapons.

The move represents one way the Obama administration intends to keep Iran in check, as it struggles to find adequate backing for new United Nations sanctions-even after a report by the U.N. nuclear watchdog concluded this week that Tehran has been developing the technologies needed to produce a nuclear weapon.

The oil-rich U.A.E. traditionally has had strong trade relations with Iran. But the ruling al Nahyan family in Abu Dhabi, the Emerati capital, is seen as one of the most hawkish against Iran among the monarchies in the Persian Gulf, and the country's leadership has openly expressed fear of an Iranian nuclear weapon.

Tehran also has regularly claimed sovereignty over three of the U.A.E.'s Persian Gulf islands, though it denies its nuclear program is for anything but peaceful purposes.

The proposed package for U.A.E. is expected to be formally presented to Congress in the coming days and would authorize the sale of up to 4,900 joint direct attack munitions, or JDAMs, along with other weapons systems.

The sale reflects the Obama administration's focus on curbing Iranian influence as it pulls the last U.S. troops out of Iraq by the end of the year. U.S. defense officials say the U.S. will have an estimated 40,000 troops in the region after the pullout.

The U.N.'s International Atomic Energy Agency in a report this week concluded Iran has conducted research on developing nuclear weapons, a finding putting pressure on the Obama administration to take new steps against the country's rulers.

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