In recent weeks, the United States has sent significant military assets - including warships and fighter jets - to the Middle East.
An American aircraft carrier is already in the vicinity of Iran and another, the USS Gerald R Ford, is in the Atlantic Ocean en route to the Middle East, AFP reports.
Donald Trump threatened Iran with military attacks earlier this year, including in connection with Iran's crackdown on demonstrations.
This week, the United States also held talks in Switzerland about Iran's nuclear energy program, which several countries fear has nuclear weapons as its ultimate goal. According to the White House, the parties were still far apart on Wednesday.
"There are many arguments to be made for an attack," White House press secretary Karoline Leavitt said regarding negotiations with Iran.
