'Deep state' critic Kash Patel nominated by Donald Trump to head ...

US president-elect Donald Trump aims to make loyalist Kash Patel the next director of the Federal Bureau of Investigation (FBI), in a move that would mean replacing the agency's current leader.

Trump announced the former advisor and Pentagon official, who has been critical of the bureau and is known for his controversial views on a so-called government "deep state," as his choice for the post on his Truth Social network on Saturday.

The FBI's current director, Christopher Wray, was appointed to a 10-year term in 2017, meaning he would either need to step down or be fired from the domestic intelligence agency.

The FBI under Mr Wray — who Trump appointed — has investigated the incoming president, sparking Trump's ire.

"Kash is a brilliant lawyer, investigator and 'America First' fighter who has spent his career exposing corruption, defending justice, and protecting the American people," Trump wrote on Truth Social.

A fierce defender of the incoming president, Mr Patel supports the Republican hardliner notion of an anti-Trump "deep state" of allegedly biased government bureaucrats working to stifle Trump from behind the scenes, even having written a book on the subject.

A son of Indian immigrants, Mr Patel served in several high-level posts during Trump's first term, including as a national security advisor and as chief of staff to the acting defence secretary.

Trump has not indicated when Mr Patel is expected to take the top job at the FBI. (AP: Alex Brandon)

"Kash did an incredible job during my first term," Trump said, adding that the nominee would work to "end the growing crime epidemic in America, dismantle the migrant criminal gangs, and stop the evil scourge of human and drug trafficking across the border."

Mr Patel first came to prominence in Trump's orbit as an outspoken critic of the FBI's investigation into potential ties between Russia and Trump's 2016 presidential campaign.

Mr Patel has signalled through interviews and public statements a determination to up-end the FBI and radically reshape its mission.

He's called for dramatically reducing its footprint and limiting its authority, as well as going after government officials who disclose information to reporters.

In an interview earlier this year on the Shawn Ryan Show, Mr Patel vowed to sever the FBI's intelligence-gathering activities from the rest of its mission and said he would "shut down" the bureau's headquarters building on Pennsylvania Avenue in Washington, DC, and "reopen it the next day as a museum of the 'deep state.'"

"And I'd take the seven thousand employees that work in that building and send them across America to go chase down criminals," he added.

In a separate interview with conservative strategist Steve Bannon, Mr Patel said he and others "will go out and find the conspirators not just in government but in the media."

Records show he has earned hundreds of thousands of dollars a year from consulting for Trump-related entities, including a political action committee and the company that owns Truth Social.

Mr Patel also helped produce "And Justice For All," a rendition of the Star Spangled Banner sung by a group of men incarcerated for their role in the January 6 Capitol riot.

Trump also nominated Charles Kushner, the father of his son-in-law Jared Kushner, as the US ambassador to France on Saturday , in the latest of several controversial picks.

Kushner "is a tremendous business leader, philanthropist, & dealmaker, who will be a strong advocate representing our Country & its interests," Trump said on his Truth Social website, adding that Jared "worked closely with me in the White House."

Charles Kushner has been announced as Trump's nominee as US ambassador to France. (Reuters: Brendan McDermid)

The choice is in keeping with Trump's pattern, so far, of selecting people, often wealthy, who are close to his family or of proven loyalty. Kushner is a multimillionaire real estate executive and former attorney; his son was a senior adviser during Trump's first term.

Trump did not mention, however, that the elder Kushner once served jail time -- a two-year sentence, most of it served in a federal prison.

Kushner, who is now 70, pleaded guilty in 2004 to 18 counts of tax evasion, witness tampering and making illegal campaign contributions.

In 2020, Trump issued him a pardon for the conviction which had resulted in him being disbarred in three states.

AFP/AP