WATCH | Donald Trump labels Stormy Daniels 'horseface' and threatens legal action

US President Donald Trump has labelled Stormy Daniels, the woman who claimed she had a sexual relationship with him, as "horseface" and threatened legal action against her.

A California federal judge threw out a defamation lawsuit filed by Daniels against Trump on Monday, saying Trump's utterances were protected by freedom of speech.

Daniels released a book on her alleged affair with Trump in which she describes his genitalia.

Trump called Daniels "a con" and said her lawyer was "third rate."