Washington DC - President Donald Trump said Tuesday he is withdrawing Hunter Biden's government bodyguards, extending his campaign of political retribution to Joe Biden's son.

Trump announced the same measure against Ashley Biden, the former president's daughter with former first lady Jill.

In a post on his Truth Social platform, Trump asserted that Hunter Biden's security detail is composed of as many as 18 people, calling it "ridiculous."

He said Hunter Biden was currently on vacation in South Africa and noted he had recently suspended US aid to the country over alleged rights violations.

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"Please be advised that, effective immediately, Hunter Biden will no longer receive Secret Service protection. Likewise, Ashley Biden who has 13 agents will be taken off the list," Trump wrote.

Federal law grants Secret Service protection to former presidents and their spouses but only to their children if they are under the age of 16.

Nonetheless, protection is often extended for a period of time to adult children.

A Secret Service spokesperson, when queried about Trump's action, told AFP: "We are aware of the President's decision to terminate protection for Hunter and Ashley Biden."

"The Secret Service will comply and is actively working with the protective details and the White House to ensure compliance as soon as possible."