Typically around 30,000 US troops are based in the Middle East, and about 40,000 troops are in the region now, according to a US official, reports AP.

That number surged as high as 43,000 last October in response to heightened tensions between Israel and Iran as well as continuous attacks on commercial and military ships in the Red Sea by the Iranian-backed Houthis in Yemen.

The US military has not yet carried out offensive operations against Iran, US military officials said on condition of anonymity to discuss military operations. The US Air Force has carried out only “defense strikes” aimed at destroying Iranian missiles in order to defend Israel.

US fighter jets joined the strikes to defend Israel, but there were no US aircraft in Iranian territory, the US officials added.