Trump to defer to defence boss on torture

US President Donald Trump will defer to Defense Secretary James Mattis regarding the use of waterboarding as an intelligence-gathering tool, even though Trump believes the practice works.

Trump said on Friday Mattis does not "necessarily believe" in waterboarding and other enhanced interrogation techniques, which many lawmakers and other rights groups denounce as torture.

"I don't necessarily agree, but I would tell you that he will override because I'm giving him that power," Trump said of Mattis during a joint press conference at the White House with visiting British Prime Minister Theresa May.

"I happen to feel that it does work. I've been open about that for a long period of time. But I am going with our leaders," Trump said.