Donald Trump speaks during a campaign rally at the Georgia State University Convocation Center in Atlanta, Georgia, on August 3, 2024
Donald Trump speaks during a campaign rally at the Georgia State University Convocation Center in Atlanta, Georgia, on August 3, 2024 AFP

Donald Trump scheduled a short-notice media event Thursday at his Florida resort as rumblings of discontent hit his presidential campaign and poll numbers surge for his election rival Kamala Harris.

Trump announced the "general news conference" in a one-sentence post on his Truth Social platform after Harris and new running mate Tim Walz have drawn large, jubilant crowds for her freshly energized Democratic bid to beat Trump in November.

Since President Joe Biden dropped out of the race last month, Harris has turned the race for the White House upside down, raking in donations and erasing Trump's lead in the polls.

Trump is described in US media reports as angry at how his campaign is now performing against Harris and how it dominates news coverage.

He is also reportedly unhappy with his young Republican running mate J.D. Vance, who has been described as a lackluster public speaker and making a poor impression with voters.