Prime Minister Boris Johnson avoided wading into the clash of British royals on Monday, praising the queen but sidestepping questions about racism and insensitivity at the palace after an interview by Prince Harry and his wife Meghan.

The former Hollywood actress, whose mother is black and father is white, accused the royal family of pushing her to the brink of suicide. In a tell-all television interview, she said someone in the royal household had raised questions about the colour of her son's skin...