The Trump-Harris debate was watched by 67 million viewers in the United States
AFP

Donald Trump said Thursday he would not take part in another debate with Kamala Harris, as the White House rivals headed back to battleground states that are set to decide a nail-bitingly close US presidential election.

The Republican former president lashed out two days after his first televised clash with the Democratic vice president, when Harris put Trump on the defensive and got under his skin with a series of barbs.

"THERE WILL BE NO THIRD DEBATE!" the 78-year-old wrote on his Truth Social platform, including in his tally the earlier debate with Joe Biden in June that drove the incumbent out of the race, and his Tuesday showdown with Harris.

Trump claimed that "polls clearly show that I won the Debate against Comrade Kamala Harris" -- despite several snap surveys that showed Harris came out well on top in the clash viewed by more than 67 million Americans.

In a rally in the key swing state of North Carolina, Harris insisted that they should debate again before the November 5 election. It wasn't clear if she was aware of Trump's statement.

"Two nights ago Donald Trump and I had our first debate and I believe we owe it to the voters to have another," Harris said to cheers from supporters in the city of Charlotte.

"Because this election and what is at stake could not be more important," added the Democrat, who heads to a second rally in Greensboro, North Carolina later on Thursday.

The 59-year-old went on to reference several Trump statements on issues including abortion and his widely mocked assertion that he had "concepts of a plan" to reform the US health care system.

The Harris campaign said earlier that she was entering a "more aggressive" phase of her White House bid and was "seeking to capitalize on her decisive debate victory and build on momentum."

Trump was taking the stage later Thursday in Tucson, Arizona, amid media reports of turmoil in his camp over the way Harris succeeded in goading him into angry responses.

He will focus on "our struggling economy and the rising cost of housing," his campaign said -- indicating an attempt to get Trump to stick to mainstream voter concerns, rather than his penchant for wild conspiracy theories and lobbing of insults.

Trump and Harris remain neck and neck in the polls with just 54 days until the election, with the result expected to hinge on a few thousand voters in half a dozen swing states including North Carolina and Arizona.

Harris has erased Trump's lead since Biden ended his reelection bid on July 21 but insists she is the underdog in perhaps the shortest and most dramatic campaign in US political history.

The election is also further stoking political tensions in an already deeply polarized nation.

The White House on Thursday condemned a false story about migrants eating pet cats and dogs in Ohio -- which Trump pushed during the debate -- as "filth" and said it put "lives in danger."

The US government has meanwhile declared the formal electoral count on January 6, 2025 a "special security event" -- amid apparent fears of a repeat of the storming of the US Capitol in 2021 by Trump supporters who refused to accept his defeat by Biden.

The announcement came as Republican Alberto Gonzales, who was attorney general under president George W. Bush, said he backed Harris because of Trump's behavior on that day made him a threat to the rule of law.

Trump and Harris though have their eyes firmly fixed on the battlegrounds.

Harris returns to pivotal Pennsylvania on Friday for campaign events in Johnstown and Wilkes-Barre before attending an awards dinner Saturday with Second Gentleman Doug Emhoff.

Trump will deliver remarks in Las Vegas on Friday on the cost of living, as he targets Nevada, yet another key swing state.

Harris's running mate Tim Walz will travel to Michigan and Wisconsin from Thursday to Saturday as part of the campaign's New Way Forward swing state tour.