US could send 120,000 troops to Middle East amid heightened Iran tensions

President Donald Trump's national security team held a meeting where Acting Defence Secretary Patrick Shanahan unveiled a plan to send 120,000 US military personnel to the Middle East if a direct confrontation with Tehran happens, The New York Times reported on Monday.

This would be roughly the same size a force that was used during the 2003 Iraq invasion, although similar action against Iran would require greater numbers of troops.

Trump has taken an even more hawkish line towards Iran since John R. Bolton was made national security adviser last April, with the former US ambassador to the UN said to be behind the reinforcements plan.

It is not clear if Trump was briefed on the Iran plan, but he has already warned Tehran not to make moves against US interests in the Middle East.

"We'll see what happens with Iran. If they do anything, it would be a very bad mistake," he said, when quizzed on whether he was seeking regime change in Iran.

The news comes amid heightened tensions between Iran and the US and its allies.

On Monday it was reported that four vessels in the UAE were allegedly sabotaged with some alleging that Iranian agents or proxies used explosives against the commerical ships.

A Saudi oil pipeline was also reportedly hit by explosive drones with Yemen's Iran-linked Houthi rebels claiming the attack.

Sending such a large military force to the Middle East would undoubtedly heighten tensions between the US and Iran that could spill out into armed conflict.

Experts told the US daily that a large force on Iran's doorstep could provide a tempting target for Tehran, having been alarmed by the military build-up. 

Some believe that Trump and Barack Obama's policies of withdrawing forces from the Middle East might have boosted the confidence of hardliners in Iran, particularly the immensely powerful Revolutionary Guards.