President Donald Trump has ordered a sweeping reorganisation of the National Security Council (NSC), significantly reducing its staff and returning many career officials to their home agencies, Associated Press and CNN reported.

Two US officials and another person familiar with the matter told the Associated Press that the move aims to streamline the NSC and align it more closely with the president's agenda.

The restructuring is being led by interim national security adviser and Secretary of State Marco Rubio, who assumed the role earlier this month following the ousting of Mike Waltz.

Waltz has since been nominated as Trump's ambassador to the United Nations.

CNN reported that more than 100 NSC officials were placed on administrative leave on Friday, a step interpreted as the most dramatic phase of the reorganisation to date.

The changes come amid ongoing turbulence within the NSC during the early months of Trump’s second term in office.

'Liquidation' of NSC

The AP reported that the NSC had already seen significant disruption earlier this year.

Around 160 detailees were sidelined shortly after Trump took office for his second term, pending a review of staffing priorities.

Waltz's removal came only weeks after Trump announced the firing of several NSC staff, reportedly in response to concerns over loyalty raised by far-right activist Laura Loomer.

This latest overhaul amounts to what one source described as a "liquidation" of NSC personnel, AP reported.

Both career detailees and political appointees are either being sent back to their respective agencies or dismissed outright.

A White House official, speaking to AP on condition of anonymity, confirmed that the restructuring — first reported by Axios — is under way, but declined to provide further details.