The former US president's response comes despite a challenge from Harris' campaign to hold another debate after her strong performance.
This week's presidential debate between former US President Donald Trump and Vice President Kamala Harris was one of the most-watched events of the election season, with the broadcast attracting more than 67 million viewers.
But on Thursday, Trump dismissed the possibility of a rerun, posting on the Truth Social platform: “THERE WILL NOT BE A THIRD DEBATE!”
Trump had already faced President Joe Biden on June 27, but concerns about the 81-year-old candidate's age grew after the Democratic incumbent's shaky performance. Less than a month later, Biden dropped out of the race and was quickly replaced by Harris.
A second debate had been planned for September 10, and despite the shifting dynamics of the race, both Harris and Trump agreed to proceed with the scheduled event, which took place in Philadelphia, Pennsylvania.
But after the debate, pundits largely gave the edge to Harris, comparing her more polished performance to Trump's disjointed one.
“Under the bright lights, the American people got to see the choice they will face at the ballot box this fall: either moving forward with Kamala Harris or moving backward with Trump,” Harris campaign manager Jen O’Malley Dillon said at the time.
Harris' team quickly challenged Trump to a subsequent debate, seeking to capitalize on the momentum. However, Trump rejected the possibility in Thursday's post on Truth Social. He also attempted to reframe the debate's fallout in his favor.
“When a boxer loses a fight, the first words out of his mouth are: 'I WANT A REMEASUREMENT,'” he wrote.
Trump expressed a similar sentiment in the minutes after the debate. Speaking to reporters, the Republican candidate argued that the challenge only came about because Harris “lost.”
But political commentators from both parties were in broad agreement that Harris had a stronger debate performance than Trump.
It was the first time Harris and Trump met in person, and the Democrat managed to provoke her increasingly irritated rival while generating several moments worthy of being recorded, full of suppressed laughter and harsh criticism.
This came despite both candidates dodging direct questions on several key policy issues.
Polls indicate that American voters also believe Harris emerged victorious from the debate. On Thursday, a poll by the Reuters news agency and the market research firm Ipsos found that 53 percent of voters who had at least some knowledge of the debate thought Harris won. Only 24 percent said the same of Trump.
A CNN snap poll released shortly after the debate also showed that a majority of viewers felt Harris outperformed Trump, and a YouGov poll showed that 54 percent of respondents said Harris won compared to Trump's 31 percent.
However, it is unclear how significant the debate will be for the November 5 election or whether the outcome will resonate with undecided voters in key states. Polls show the race remains very close.
The Reuters/Ipsos poll also found that a majority of registered voters surveyed are satisfied with having just one debate between Harris and Trump.
Fifty-four percent thought one debate was sufficient, while 46 percent said they wanted a second debate.
