Donald Trump has reversed his position on torture, saying a single meeting with a retired Marine Corps general changed his mind.

During the rancorous US presidential election campaign, the president-elect claimed that "torture works" and described waterboarding as a "minor form" which he was "absolutely fine" with. The Republican even pledged to bring back "a hell of a lot worse than waterboarding."

However, in a wide-ranging interview with the New York Times on Tuesday (22 November), Trump claimed to have shifted his view on the effectiveness of waterboarding after speaking to retired Marine General James Mattis, who is being "seriously, seriously considered" for secretary of defense.

"He said, 'I've never found it to be useful,'" Trump said. Explaining Mattis' view that building trust is a far more powerful interrogation technique than torture, Trump quoted the 11th commander of the US Central Command as saying: "'Give me a pack of cigarettes and a couple of beers, and I'll do better.'"

"I was very impressed by that answer," Trump said, adding that torture is "not going to make the kind of a difference that a lot of people are thinking."

During the campaign trail, Trump insisted that he would reinstate waterboarding and other torture techniques used to extract information from suspected terrorists. "Don't tell me it doesn't work – torture works," the Republican said at a retirement community in South Carolina in February. "Okay, folks? Torture – you know, half these guys [say]: 'Torture doesn't work.' Believe me, it works. Okay?"

A 2014 US Senate report on the harsh methods used by the CIA in the aftermath of 9/11 found that "seven of the 39 CIA detainees known to have been subjected to the CIA's enhanced interrogation techniques produced no intelligence while in CIA custody ... Other detainees provided significant accurate intelligence prior to, or without having been subjected to these techniques."

"Freedom from Torture welcomes Donald Trump's reversal on torture," Sonya Sceats, Director of Policy and Advocacy at Freedom from Torture told IBTimes UK. "The US president-elect is right that torture is ineffective. Countless survivors have told us how during torture they admitted to anything, just to make it stop.

"But even if it did work, torture is legally and morally wrong," she added. "It is not befitting of any state that wishes to be respected by the international community."

Trump's disagreement with himself is the latest in a series of flip-flops – 15 in 15 days to be precise, according to Politico. Other self-contradictions from the incoming commander-in-chief include his stance on Obamacare, gay marriage, backing away from his campaign pledge to pursue Hillary Clinton's prosecution, his view on US generals and his predecessor.