Donald Trump on Tuesday hit back at Robert De Niro, calling him a "very low IQ individual," after the Oscar-winning actor's expletive-laden attack on the American president on live television.

Two days after De Niro's outburst on the stage of the Tony Awards ceremony in New York, Trump said he had watched the clip "and (I) truly believe he may be punch drunk."

Representatives for De Niro did not immediately return a request for comment.