Washington, May 14 (IANS): At a meeting of US President Donald Trumps top national security aides last week, Acting Defence Secretary Patrick Shanahan presented an updated military plan that envisions sending as many as 120,000 troops to the Middle East should Iran attack American forces or accelerate work on nuclear weapons, administration officials said.

The high-level review of the Pentagon's plans was presented during a meeting on May 9 about broader Iran policys, The New York Times quoted the officials as saying on Monday.

It was held days after what the Trump administration described, without evidence, as new intelligence indicating that Iran was mobilising proxy groups in Iraq and Syria to attack American force.

As a precaution, the Pentagon has moved an aircraft carrier, B-52 bombers, a Patriot missile interceptor battery and more naval firepower to the Gulf region.

The revisions were ordered by hard-liners led by John Bolton, Trump's National Security Adviser. They however, did not call for a land invasion of Iran, which would require vastly more troops.

It remains uncertain whether Trump, who has sought to disentangle the US from Afghanistan and Syria, ultimately would send American forces back to the Middle East.

It is also unclear whether the President has been briefed on the number of troops or other details in the plans.

On Monday, when asked about if he was seeking regime change in Iran, Trump said: "We'll see what happens with Iran. If they do anything, it would be a very bad mistake."

"It's going to be a bad problem for Iran if something happens," he added.

European allies who met Secretary of State Mike Pompeo on Monday said that they were worried that tensions between Washington and Tehran could boil over, possibly inadvertently.

According to The New York Times, deploying such a robust air, land and naval force would give Tehran more targets to strike, and potentially more reason to do so, risking entangling the US in a drawn out conflict.

It also would reverse years of retrenching by the American military in the Middle East that began with former President Barack Obama's withdrawal of troops from Iraq in 2011.

The report comes as several oil tankers were reportedly attacked or sabotaged off the coast of the United Arab Emirates on Sunday.

Saudi Arabian officials are investigating the apparent sabotage, and American officials suspect that Iran was involved.

An Iranian Foreign Ministry spokesman called it a "regretful incident".