Michael Flynn, who once used the phrase “Islamic ideology sick” on social media, named US national security adviser.

US President-elect Donald Trump has named Michael Flynn, a controversial ex-army general, who once said that “fear of Muslims is rational” and used the phrase “Islamic ideology sick”, as his national security adviser.

In an interview with Al Jazeera first published in July, Flynn, 57, defended his remarks on social media, saying leaders in the Muslim-majority countries need to do more and “stand up”.

“Islam is a political ideology based on religion,” Flynn told Mehdi Hasan , host of Al Jazeera’s Upfront, in an interview during the Republican National Convention in Cleveland, Ohio.

After an attack in Nice, France , Flynn wrote on Twitter: “I dare Arab & Persian world ‘leaders’ to step up to the plate and declare their Islamic ideology sick and must [be] healed.”

READ MORE: Trump ally defends ‘Islamic ideology sick’ remarks

In a separate interview with Al Jazeera in May, Flynn also refused to condemn Trump’s proposal to ban Muslims from entering the United States.

“What I support … is that we must understand where these individuals are coming from,” Flynn said, adding that he supported the “vetting of individuals and the proper screening of individuals who are coming from certain parts of the world, like Syria”.

In February, the next US president’s presumptive head national security adviser also tweeted a video link with the message that “Fear of Muslims is RATIONAL”.

With three decades of military experience, Flynn served as director of Defense Intelligence Agency from 2012 until he was ousted in 2014.

He served in Iraq and Afghanistan and is a Bronze Star recipient.

‘Right-wing nutty’

A native of Rhode Island, Flynn was one of nine children. His brother Charlie is also a high-ranking army official.

Like Trump, Flynn supports a de-escalation of tensions with Russia.

He has appeared numerous times on Russian state broadcaster Russia Today (RT) and sat next to Russian President Vladimir Putin at an RT event in Moscow last year.

According to The New York Times, his consulting firm, Flynn Intel Group, has ties to nations in the Middle East and lobbies for the Turkish government.

Flynn’s appointment is not subject to Senate approval.

Flynn advised Trump during his presidential campaign. In hacked emails, former Secretary of State Colin Powell called Flynn, a registered Democrat, “right-wing nutty.”

Flynn led chants of “lock her up”, in regard to Democratic candidate Hillary Clinton, from the podium at July’s Republican convention.

Ranking Democratic member of the House Intelligence Committee, Adam Schiff, tweeted Friday: “Have deep concerns about Gen Flynn as a possible National Security Advisor. Worried about an impulsive president with a volatile advisor.”

On social media, the reported appointment was also greeted with pessimism.

ISIS must be thrilled at prospect of Michael Flynn as Nat Sec Adv,Muslim registration in US. Dream of a war between West and Islam so close! — Norman Ornstein (@NormOrnstein) November 17, 2016

https://twitter.com/ezraklein/status/799611368651378688