A controversial former aide to US President Donald Trump is to give a keynote address at a respected anti-terrorism conference in Israel next week, organisers said Wednesday.

Sebastian Gorka, who left the White House on August 25 amid conflicting claims over whether he resigned or was fired, has been accused of ties to far-right groups.

His claimed counter-terrorism knowledge has also been repeatedly questioned by peers.

Gorka is due to give a keynote address on Monday at an annual anti-terrorism conference organised by IDC Herzliya, a private college.

"Sebastian Gorka was invited due to his position as President Trump's senior adviser on counter-terrorism and his up-close familiarity with the process of decision-making in the Trump administration," IDC Herzliya said in a statement in response to AFP questions on the appearance.

"Gorka is a relevant and important source for understanding the US governmental policy on terrorism, which can contribute extremely relevant information for experts participating in the conference."

"The fact that he only recently left his position at the White House may give him more liberty to share his experience, which will enrich the knowledge of the audience," the college added.

A range of politicians, experts and foreign dignitaries usually speak at the conference, called the "World Summit on Counter-Terrorism".

Gorka is scheduled to speak on the same day as former French prime minister Manuel Valls, while other scheduled speakers include Israeli Defence Minister Avigdor Lieberman.

Various foreign experts are also due to speak at the conference from September 11-14.

Before leaving the White House, Gorka, 46, had become a familiar face on television, offering a bombastic defence of the US president in a strong English accent.

Born in London to Hungarian parents, he became a US citizen in recent years.

Source: AFP