Thursday's debate between President Donald Trump and Democratic challenger Joe Biden will feature a mute button to allow each candidate to speak uninterrupted.
Organisers say the innovation will help avoid the disruptions that marred the first match-up.
The Presidential Commission on Debates said on Monday each candidate's microphone would be silenced to allow the other to make two minutes of opening remarks at the beginning of each 15-minute segment of the debate.
Both microphones will be turned on to allow a back and forth after that time.
Mr Trump's campaign immediately objected to the change but said he would still take part.
"President Trump is committed to debating Joe Biden regardless of last-minute rule changes from the biased commission in their latest attempt to provide advantage to their favoured candidate," campaign manager Bill Stepien said.
The Biden campaign did not immediately respond to a request for comment.
The news came the day the number of Americans voting early ahead of Election Day on 3 November crossed the 30 million mark and as Mr Trump tries to reframe a contest in which national and state opinion polls show him trailing.
Mr Trump repeatedly interrupted Biden during a chaotic and ill-tempered debate on September 29 and Biden responded with insults.
Mr Trump backed out of a second scheduled debate set for last Thursday over a disagreement about the virtual format following his COVID-19 infection.
At that time, he raised concerns about having his microphone muted.
"You sit behind a computer and do a debate - it's ridiculous, and then they cut you off whenever they want," Trump said in an 8 October interview on Fox Business.
On Monday, Mr Trump's campaign said it was unhappy with the announced set of topics for Thursday's debate, arguing it should focus more on foreign policy and complaining the nonpartisan group was tilted toward Mr Biden.
Mr Biden's campaign said both sides previously agreed to let moderators choose the subjects.
It said Mr Trump wanted to avoid discussing his stewardship of the coronavirus pandemic, which surveys show is the top voter issue.
"As usual, the president is more concerned with the rules of a debate than he is getting a nation in crisis the help it needs," Mr Biden's spokesman TJ Ducklo said.
