Bob Geldof has called on young people to boycott Elon Musk's companies and described the U.S. government's cancellation of foreign aid as a "war on the weakest and most vulnerable".

Speaking to local news outlets ahead of his show in Adelaide, Australia this week, the musician and Live Aid founder said that he is receiving dozens of emails a day from charities in Africa following American President Donald Trump's recent decision to freeze foreign aid.

He said that the emails described situations where women were losing protection from brutal assaults, and that AIDS patients were forced to ration their medication before dying.

“The strongest nation on Earth, the most powerful men on the planet, the richest men in the world, have decided to wage war on the weakest and most vulnerable," Geldof told The Advertiser.

The Boomtown Rats frontman also said that if he were a teenager again that he'd be leading boycotts of Elon Musk's businesses Tesla, X and Starlink.

“Empathy works," Geldof said. "That flies in the face of that sociopathic moron Elon Musk, who last week said the weakness of western civilisation is empathy. Wrong."

Geldof added that social media has "changed everything" and that politics was no longer “filtered through the lens of rock’n’roll”, concluding that an event like Live Aid would be less likely to succeed today.