Trump did not specify what had prompted his morning outburst, but it comes as his administration pursues multiple criminal investigations against his perceived enemies.

“George Soros, and his wonderful Radical Left son, should be charged with RICO because of their support of Violent Protests, and much more,” the president wrote on his Truth Social platform, referring to a law against taking part in a criminal organisation.

Long-standing conspiracy theories involving the Soros family swirled again in June, as street protests broke out in Los Angeles against a ramp up of immigration raids.

Trump used the demonstrations as justification to deploy the national guard and marines into the Democratic-run city.

Fact-checkers including AFP debunked several images which circulated online at the time, purporting to show that nonprofit groups backed by the Soros family had strategically placed bricks to hurl at police.

Hungarian-born Soros, 95, has long been a bogeyman for the far right in Europe and the US for his financial support of progressive causes.

He has been baselessly blamed for propagating migrant crises in Europe and on the southern border of the US, as well as for orchestrating mass protests against police brutality after the 2020 killing of George Floyd.

Soros announced in 2023 that he would hand over control of his philanthropic empire to his son Alexander.

Joe Biden awarded the elder Soros a presidential Medal of Freedom in January shortly before Trump took office, citing Soros’s support for “organisations and projects across the world that strengthen democracy, human rights, education and social justice”.