Robert De Niro told an awards ceremony a speech he was reading had been edited without his knowledge, removing critical comments about Donald Trump.

The actor initially appeared confused while reading from an autocue on stage at the Gotham Awards in New York.

He then told the audience: "The beginning of my speech was edited, cut out. I didn't know about it."

He went on to read the original script, referring to Trump's "lies" among other things, after finding it on his phone.

The Gotham Awards kicked off this year's film awards season, and De Niro was introducing an honour for Killers of the Flower Moon, in which he appeared.

Seeming to struggle with the autocue, he said: "I'm going to go back, I'm sorry. There was a mistake in this. I'll keep going. Just keep scrolling. Can we go back? Sorry."

After a film clip was played, he told the crowd that part of his speech had been cut and turned to his phone to read it instead.

"History isn't history any more," he said. "Truth is not truth. Even facts are being replaced by alternative facts and driven by conspiracy theories and ugliness."

He referred to students in Florida being told slaves developed skills "for their personal benefit", and said the entertainment industry "isn't immune to this festering disease".

He singled out actor John Wayne, quoting 1971 remarks about Native Americans in which he said: "I don't feel we did wrong taking this great country away from them."

'How dare they?'

De Niro continued: "Lying has become just another tool in the charlatan's arsenal. The former president lied to us more than 30,000 times during his four years in office, and he's keeping up the pace in his current campaign of retribution.

"But with all his lies, he can't hide his soul. He attacks the weak, destroys the gifts of nature and shows disrespect, for example, by using Pocahontas as a slur," referencing the former president's nickname for Senator Elizabeth Warren.

"This is where I came in and I saw that they edited all that."

De Niro, who has been vocal in his criticism of Trump in the past, then said he was supposed to thank the Gotham Awards and Apple, which made Killers of the Flower Moon. "But I don't feel like thanking them at all for what they did. How dare they do that actually?"

Apple and the award organisers have not commented.

The actor went on to introduce his co-stars to accept the Historical Icon & Creator Tribute award.

One of them, Lily Gladstone, also won the prize for best lead performance - but not for Killers of the Flower Moon. She won for another film, The Unknown Country, in which she plays a woman who goes on a road trip after her grandmother dies.

The top prize for best feature went to drama Past Lives, about childhood sweethearts in South Korea who are separated when one emigrates to the US.

French drama Anatomy of a Fall won two awards, while Netflix series Beef won in two TV categories.