The heir to the throne was speaking at a fundraiser for World Jewish Relief, a humanitarian agency, when he made the comments.
The Prince of Wales was recalling the story of the “indescribable persecution” Holocaust survivor and former Olympic weightlifting champion Ben Helfgott faced during World War II.
“The work of World Jewish Relief enables us to rally together to do what we can to support people practically, emotionally and spiritually,” he said.
“Particularly at a time when the horrific lessons of the last war seem to be in increasing danger of being forgotten," he added.
The Prince of Wales' reference to “the horrific lessons of the last war” were viewed by some in the audience as an attack on the Trump administration and the recent ban on Muslim immigration.
The Prince said Mr Helfgott’s experience reminded us not to forget history, saying: “To meet Ben, and others who, like him, have endured indescribable persecution, is to be reminded of the danger of forgetting the lessons of the past.”