The US removed military aircraft from RAF Mildenhall on Monday following an Iran-linked threat. Two refuelling tankers moved to Germany after the Pentagon previously recalled B-1 bombers from RAF Fairford. While the UK Ministry of Defence said assets move regularly, the US president said a return to war is unlikely.

The US has evacuated military aircraft from a second British air base following an Iran-linked threat, according to people familiar with the matter.

Two US Air Force refuelling tankers were removed from RAF Mildenhall in Suffolk on Monday morning and diverted to Germany, while other American military tankers were diverted to other locations in the afternoon, flight-tracking data showed.

The transfer of the multimillion-dollar assets, first reported by the Wall Street Journal, came after the Pentagon last month recalled all its B-1 bombers from RAF Fairford in Gloucestershire.

The bombers returned to the US after a security incident at the base.

In July, Iran's Islamic Revolutionary Guard Corps namechecked RAF Fairford, which has been used by the US to launch strikes against Iran, as a legitimate target for reprisal attacks.

The US subsequently upgraded security at RAF Mildenhall and RAF Lakenheath, another base in Suffolk used by the American military, according to reports.

It is not clear whether this week's removal of planes from Mildenhall was in response to a specific and imminent threat or a more diffuse, longer-term risk.

The UK Ministry of Defence said: "We do not routinely comment on the activity of other nations. Aircraft and other assets move regularly according to operational requirements."

Donald Trump is weighing whether to proceed with fresh strikes on Iran, having moved additional materiel to the region.

However, on Monday the US president said on social media that a return to war with Tehran was "unlikely" and that "at this point, taking military action doesn't seem to be a very necessary thing".

He said last month that initial abrupt evacuation of US bombers from RAF Fairford came after "some threats" were made to the UK air base.

UK Prime Minister Andy Burnham said there were "strong indications" that Iran was involved in an incident near Fairford in September. Tehran has denied any role in the incident.

Seven arrests have been made by UK counterterror police in relation to the incident. All have been released on bail while investigations continue.

Britain also imposed new sanctions on Iran and summoned its ambassador in response.