The top US defence official has presented an updated military plan to President Donald Trump's administration that envisions sending up to 120,000 troops to the Middle East should Iran attack American forces or accelerate work on nuclear weapons, the New York Times and Reuters reported on Monday.
Citing unnamed administration officials, the Times said Acting Defense Secretary Patrick Shanahan presented the plan at a meeting of Trump's top security aides on Thursday.
Reuters could not immediately confirm the report.
The White House did not immediately respond to a request for comment. The Pentagon declined to comment.
Tensions between Iran and the United States have intensified since Trump pulled out of a 2015 international deal to curb Iran's nuclear activities and imposed increasingly strict sanctions on Tehran.
Trump wants to force Tehran to agree to a broader arms control accord and has sent an aircraft carrier, and B-52 bombers to the Gulf in a show of force against what US officials have said are threats to US troops in the region.
Iran has said the US is engaging in "psychological warfare," called the US military presence "a target" rather than a threat and said it would not allow its oil exports to be halted.
The Times said among those attending the Thursday meeting were Trump's national security adviser John Bolton, CIA Director Gina Haspel, Director of National Intelligence Dan Coats, and Chairman of the Joint Chiefs of Staff General Joseph Dunford.
Several plans were detailed, the Times said, and "the uppermost option called for deploying 120,000 troops, which would take weeks or months to complete."