Format to change after rancorous first debate between Trump and Biden

The first presidential debate between Donald Trump, second from left, and Joe Biden, second from right, was marked by interruptions (Julio Cortez/AP)

The US presidential debate commission says it will make changes to future debate formats to avoid a repeat of the disjointed first meeting between Donald Trump and Joe Biden.

Moderator Chris Wallace struggled to keep control of the debate because of frequent interruptions, primarily by the president.