The microphones of US President Donald Trump and his Democratic rival Joe Biden will be muted during segments of Thursday's presidential debate, the last direct face-off before the November 3 election, it was announced.

The Commission on Presidential Debates (CPD) said the decision was taken on after it met on Monday to discuss changes to the format of the debate which will take place at the Curb Event Centre, Belmont University in Nashville, Tennessee, CNN reported.

"We realize, after discussions with both campaigns, that neither campaign may be totally satisfied with the measures announced today.

"One may think they go too far, and one may think they do not go far enough. We are comfortable that these actions strike the right balance and that they are in the interest of the American people, for whom these debates are held," it said in a statement.

Following the first presidential debate on September 29 which took a chaotic turn, insults such as "clown", "liar", "just shush for a minute" and "keep yapping" took centre-stage as the two rivals tore into each other, the CPD had announced that it was mulling changes to the format.

According to the CPD's statement, at the start of each of the six segments of the debate, each candidate will be given two minutes to answer an initial question.

During that portion, the opposing candidate's microphone will be muted.

An informed source told CNN on Monday that the decision on muting the microphones was unanimous by the CPD members.

"This is not a change to rules but rather a move to promote adherence to rules that have been agreed to by both campaigns.
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A change to the rules would have required protracted and ultimately, in our view, unworkable negotiations between the two campaigns," the source told CNN.

Reacting to the decision, Trump told reporters: "I'll participate. I just think it's very unfair."

Confirming the President's participation, Trump campaign communications director Tim Murtaugh termed the CPD's decision an "attempt to provide advantage to their favoured candidate".

The second presidential debate which was scheduled to take place on October 15 was cancelled after the CPD had suggested holding it in a virtual format following Trump's Covid-19 diagnosis.

But the President rejected the idea and declared that he wouldn't participate, leading to its scrapping.