US President Donald Trump has described the killing of a Saudi journalist as a botched operation and a “bad original concept”.

Speaking to reporters at the White House, Trump said the entire operation was a fiasco as the US took its first steps toward punishing the Saudis by moving to revoke visas of the suspects.

“They had a very bad original concept,” Trump said. “It was carried out poorly, and the cover-up was one of the worst cover-ups in the history of cover-ups.