Trump and Harris agree on debate showdown in September

US Republican presidential candidate Donald Trump and Democratic opponent Kamala Harris will debate on September 10 on ABC, setting up the first face-to-face matchup between the rivals in what polls show is an extremely close race.

In a rambling news conference at his Palm Beach, Florida, residence, Trump said he wanted additional debates on September 4 and 25 that would air on Fox and NBC.

Harris said in a post on X that she was looking forward to the September 10 debate after Trump "finally committed." She told reporters after a campaign stop in Detroit that she was open to discussing more debates.

Trump had previously suggested he might back out of the ABC debate, which was scheduled before Harris, the US vice president, replaced President Joe Biden as the Democratic presidential candidate less than three weeks ago, upending the contest.

An Ipsos poll published on Thursday found Harris had widened her lead over Trump since late July. She leads Trump 42% to 37%, compared to a July 22-23 Reuters/Ipsos survey, which showed her up 37% to 34% over Trump.

The news conference was Trump's first public appearance since Harris selected Minnesota Governor Tim Walz as her running mate on Tuesday.

Harris and Walz have headlined rallies in the battleground states of Pennsylvania, Michigan and Wisconsin this week, drawing tens of thousands of attendees in a fresh sign of how her late entry into the race has galvanized Democrats.

Her rapid rise has sent Trump's team scrambling to recalibrate their strategy and messaging. Opinion polls show Harris has erased the lead Trump had built over President Joe Biden, and Democrats have raked in hundreds of millions of dollars from voters and big donors in a matter of weeks.

Trump insisted on Thursday he has not altered his approach to the race, arguing that Harris shares responsibility for Biden's record.

In a question-and-answer session with reporters that stretched beyond an hour, Trump hopped from topic to topic, claiming Harris and Walz were weak candidates who were already dropping in the polls.

Nevertheless, Trump lamented that he isn't able to face Biden in the Nov. 5 election, suggesting the president was a victim of an unconstitutional plot to dislodge him from atop the Democratic ticket.

Biden dropped his faltering reelection bid under pressure from fellow Democrats worried about his chances of victory after a poor debate performance against Trump.

Asked about his controversial comments last week that Harris, who is of Black and Indian decent, recently "happened to turn Black," Trump said: "You'll have to ask her that question, because she's the one that said it, I didn't say it.... To me it doesn't matter. But to her, from her standpoint, I think it's very disrespectful to both, really, whether it's Indian or Black, I think it's very disrespectful to both."

Trump's initial comments, delivered to an audience of Black journalists, drew widespread condemnation and left donors and aides baffled and alarmed.

Trump on Thursday also mocked the size of Harris' campaign crowds, even though they have matched his of late. He falsely claimed the size of the crowd he addressed on Jan. 6, 2021 – the day his supporters stormed the US. Capitol – was as large as those who packed the National Mall in Washington for Dr. Martin Luther King's "I Have a Dream" speech in 1963.

"We actually had more people," Trump said. "But I'm ok with it, because I liked Dr. Martin Luther King."

Echoing a recent attack line from his campaign, Trump criticized Harris for not doing a press interview since launching her campaign.

"She can't do an interview. She's barely competent," Trump said, later again calling her "nasty," a go-to line that he often uses to disparage female critics.

Trump has conducted a steady stream of media interviews, though they are usually with friendly, right-leaning outlets and reporters. On Wednesday, he called into the "Fox & Friends" morning program and took questions from the program's hosts.

Trump announced the news conference on Thursday morning on his social media platform, and only a select group of reporters were given the advance notice needed to travel to his Florida resort in time. Reuters was not extended an invitation.

Harris answered a handful of questions from reporters after meeting with auto workers in Detroit on Thursday, following the United Auto Workers union's endorsement of her candidacy. She said she wants to schedule a sit-down interview "before the end of the month."