The operation, which is planned to last several weeks, has not yet been approved by US President Donald Trump. According to the Washington Post's sources, the operation may include raids near the Strait of Hormuz, but is not expected to constitute a full-scale invasion.
US Secretary of State Marco Rubio said on Friday that the US can "achieve its objectives without ground forces", but according to the newspaper, planning for the operation is well advanced.
The US has been sending more troops to the Middle East in the past week. For example, the amphibious ship USS Tripoli - with around 2,500 Marines on board - recently arrived in the region.
