James Mattis and Donald Trump
James Mattis and Donald TrumpReuters

US President Donald Trump on Tuesday confirmed a plan was in the works to take out Syrian President Bashar Al-Assad in 2017 and that he was supportive of it, but former Defense Secretary James Mattis was opposed, The Hill reports.

“I would've rather taken him out. I had him all set. Mattis didn’t want to do it. Mattis was a highly overrated general," Trump was quoted as having said on "Fox & Friends."

Trump added that he did not regret the decision not to target Assad, saying he "could've lived either way."

The comments confirm a piece of reporting from 2018 that Trump disputed at the time.

Journalist Bob Woodward reported in his 2018 book, "Fear," that Trump urged Mattis that the US should “f------ kill” Assad following an April 2017 chemical attack on civilians in Syria.

Mattis reportedly went along with the President’s demands during the phone call, but immediately told aides after hanging up that they would take a “much more measured” approach.

At the time, Trump responded to the book in a series of tweets, calling it a “con on the public”.

During Tuesday’s interview, Trump criticized Mattis at length, saying, "To me, he was a terrible general. He was a bad leader, and he wasn't doing the job with ISIS," Trump said. "He was not doing the job in Syria or Iraq with respect to ISIS."

Host Brian Kilmeade interjected to praise Mattis as a great American who served his country.

"I don't say he is a good American or a bad American," Trump replied. "I just say he didn't do a good job."

Mattis resigned in December of 2018 amid disagreements with Trump over plans to pull all US troops out of Syria.

Trump had hinted in an interview several months earlier that Mattis "could be" leaving and referred to him as "sort of a Democrat".