The White House has defended a series of reforms to the US National Security Council, made in an executive order by Donald Trump, which will dramatically reduce the influence of military experts.

The changes have been called “stone cold crazy” by Susan Rice, who served for the last four years as Barack Obama’s National Security Adviser, and drew criticism from senior Republicans including Senator John McCain.

Mr Trump’s order dictated that the chairman of the Joint Chiefs of Staff and the Director of National Intelligence (DNI) would no longer routinely be required to attend top-level meetings of the NSC, the primary cabinet forum for the consideration of matters of national security.

Instead, the President has given Steve Bannon, his Chief Strategist, a place on the council. Mr Bannon is the former publisher of the right wing website Breitbart News, an avowed nationalist who described his site as a platform for the white supremacist “Alt-Right”.

Ms Rice retweeted a Trump critic who said Mr Trump “loves and trusts the military so much he just kicked them out of the National Security Council and put in a Nazi in their place”.

Providing her own commentary, she added: “This is stone cold crazy. After a week of crazy. Who needs military advice or intell to make policy on ISIL (Isis), Syria, Afghanistan, DPRK (North Korea)?”

She suggested Mr Trump was reducing the importance of the NSC by allowing Vice-President Mike Pence to chair some meetings, something which “never happened under Obama”.

And she said the chairman of the Joint Chiefs of Staff and the DNI were being “treated as after-thoughts in the [NSC] cabinet level principals meetings” – adding: “And where is CIA?? Cut out of everything?”

Mr Trump’s executive order states that the top two military chiefs would only attend meetings where “issues pertaining to their responsibilities and expertise are to be discussed”.

According to CNN, intelligence chief James Clapper was always included in NSC principals’ meetings during the Obama administration.

Senator McCain said he approved of the national security team Mr Trump had assembled, with the key exception of Mr Bannon.

“I am worried about the NSC, who are the members of it and who are the permanent members of it. The appointment of Mr Bannon is something which is a radical departure from any NSC in history," he told CBS’s “Face the Nation”. “It's of concern, this quote ‘reorganisation’.”

White House chief of staff Reince Priebus played down the changes on NBC News’ “Meet the Press”, saying the Joint Chiefs chairman and DNI could attend the NSC “anytime that they want to be included”.

Sean Spicer, Mr Trump’s spokesman, told ABC News the reforms were designed to “streamline the process for the President to make decisions in key important intelligence matters”.

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He praised General Mike Flynn, who will run the NSC as Mr Trump’s National Security Adviser, as “ leader… who probably understands the reforms that are needed better than anybody else”. General Flynn was head of the Defense Intelligence Agency until 2014, when he was asked to step down by senior intelligence leaders.