WASHINGTON: Israel shared intelligence with the United States this week about a new and "specific" plan by Iran to assassinate President Donald Trump, US media reported on Thursday (Jul 9).

The reports come as renewed US and Iranian attacks raised fears of a return to all-out war, and after Trump's puzzling use of an old plane to depart from Turkey after the NATO summit.

Washington has monitored "a steady drumbeat" of intelligence about possible plans to assassinate Trump, "but the warning from Israel was new and concerned a specific plot", CNN reported, citing unnamed sources familiar with the matter.

The Wall Street Journal, also citing unidentified sources, said the intelligence described a "fresh" plot.

Tehran has for years vowed to hit back at Trump for ordering the assassination of Iranian general Qassem Soleimani in January 2020, during his first term.

When AFP contacted the White House about the reports, an unidentified official pointed to Trump's remarks from Wednesday.

"They want to take out the US leader - me. I'm on whatever list. I saw this morning I'm on every single one of their lists," Trump told reporters aboard Air Force One as he flew home from a NATO summit.

Trump used his old Air Force One plane to leave Turkey, where the summit took place, sending his new Qatari-gifted jet on ahead to Britain, where he switched planes for the journey to Washington.

The switch from the new jet on its maiden foreign trip sparked speculation it was because its security features were lacking - particularly as the US launched fresh strikes against Iran, which borders Turkey.

The New York Times reported late Wednesday that the switch was made at the request of the US Secret Service "as a security precaution".

In a press conference, Trump sidestepped safety questions but alluded to previous alleged assassination attempts by Iran.