US President Joe Biden told a climate heckler to “shush up” after they interrupted a speech he was giving in Arizona.

Mr Biden was speaking at an event honouring the late Republican senator John McCain when the protester shouted that the president should declare a climate emergency, saying the country needed his leadership.

The president responded by telling the man to “shush up” and offering to meet him later.

Mr Biden used the speech to step up his criticism of Donald Trump, accusing him of plotting to subvert the US constitution.

He described the former president and his supporters as a dangerous threat to democracy, saying Mr Trump’s campaign for re-election was motivated by vengeance and vindictiveness.