At least 30 US military planes have been moved from bases in America to Europe over the past three days, flight tracking data reviewed by BBC Verify has shown.
The planes in question are all US military tanker aircraft used to re-fuel fighter jets and bombers. According to Flightradar24, at least seven of these - all KC-135s - stopped off in US airbases in Spain, Scotland and England.
The flights come as Israel and Iran continue to exchange strikes, after Israel launched an operation on Friday that it said was to destroy Tehran's nuclear programme.
It is unclear whether the US movements are directly connected to the conflict, but one expert told BBC Verify that the tanker aircraft flights were "highly unusual".
Justin Bronk, a senior analyst with the Royal United Services Institute (Rusi) think tank, said that the deployments were "highly suggestive" that the US was putting in place contingency plans to "support intensive combat operations" in the region in the coming weeks.
