United States President Donald Trump was secretly moved from one aircraft to another during a security operation following intelligence about a possible Iranian threat to his flight, according to US media reports.

The incident occurred last month as Trump prepared to leave Ankara, Turkey, after attending a NATO summit.

The Washington Post, which first reported details of the operation, said Trump initially boarded an older Air Force One aircraft in view of television cameras before security officials quietly changed his travel arrangements.

A United States official familiar with the operation said the President was subsequently transferred to another aircraft without the change being publicly disclosed at the time.

Officials cited by CBS News said American authorities had detected what they regarded as a credible and immediate Iranian threat against the aircraft Trump was expected to use.

The security concern reportedly emerged against the backdrop of heightened tensions between Washington and Tehran following renewed US military action against Iran.

The decision to alter Trump’s travel arrangements was consequently taken at short notice.

The President was moved to a smaller C-32A military aircraft, a modified Boeing 757 commonly used for senior US government officials, and flown discreetly to the United Kingdom.

Journalists and some White House officials who remained aboard the aircraft Trump originally entered were reportedly not informed that the President had switched planes.

As a result, they continued with the initial travel arrangements without knowing that Trump was no longer aboard.

US Defence Secretary Pete Hegseth was reportedly among the few senior officials who accompanied the President during the change.

The operation was intended to conceal Trump’s actual location and travel route while security officials responded to the threat.

After arriving in the United Kingdom, Trump was reportedly transferred back to the older Air Force One aircraft.

He later disembarked in view of journalists before boarding the Boeing 747-8 aircraft previously donated by Qatar and flying back to Washington.

Trump and US officials had earlier publicly indicated that he would leave Turkey aboard the older Air Force One rather than the Qatari aircraft.

Officials had raised concerns about security modifications still required on the donated plane.

NBC News reported that White House Communications Director Steven Cheung did not dispute The Washington Post account of the operation.