Former president Donald Trump appeared to again mix up his likely 2024 rival Joe Biden with his Democratic Party predecessor Barack Obama at a rally in New Hampshire, which looms as a crucial state in next year’s Republican presidential primaries.

Speaking to a crowd of supporters in the city of Claremont on Saturday afternoon, he praised Hungary’s authoritarian leader, Viktor Orban, claiming the prime minister had called on Mr Obama — not Mr Biden — to resign as US president, allowing Mr Trump to start a second term so he could restore global peace.

“They were interviewing [Orban] two weeks ago and they said: ‘What would you advise President Obama? The whole world seems to be exploding and imploding’.

“And he said: ‘It’s very simple. He should immediately resign and they should replace him with President Trump, who kept the world safe’.”

Mr Obama served as the 44th president of the US between 2009 and 2017, preceding Mr Trump who defeated Hillary Clinton in the 2016 election before Mr Biden won the 2020 election.

In recent weeks, Mr Trump has warned about the imminent outbreak of World War II, referred to Mr Orban as the leader of Turkey, incorrectly claimed that Hungary bordered Russia and mixed up Sioux City, Iowa — where he was giving a campaign speech on October 29 — with Sioux Falls, South Dakota.

His latest misstep came during a weekend that the 77-year-old received a boost with the endorsement of Bernie Marcus, the billionaire co-founder of retail giant, Home Depot.

This was despite the dismal showing of Trump-backed candidates in last week’s state elections that again saw the Democrats over perform, defying Mr Biden’s near-record unpopularity.

According to New York Times polling, Mr Biden trails Mr Trump in key swing states he won in 2020.

“Let’s face it: Donald Trump is going to win the nomination,” the 94-year-old Mr Marcus, who is worth a reported $US8 billion ($12.6 billion), wrote in an opinion piece for RealClearPolitics.

“We cannot let his brash style be the reason we walk away from his otherwise excellent stewardship of the United States during his first term in office.

Other rich Republican backers have yet to commit to Mr Trump, including a group of GOP mega-donors and billionaires who had urged Virginia Governor Glenn Youngkin to enter the presidential race.

But after the GOP’s disappointing performance last Tuesday night — they narrowly lost both state legislative chambers in Virginia — Mr Youngkin put his presidential bid on hold, announcing he was “not going anywhere”.

During his freewheeling New Hampshire speech, Mr Trump admonished the crowd for the unusually early 2pm start time — his rallies are usually in the evening — saying that it had “screwed up my whole day”.

He also looked to leverage the wars in Gaza and Ukraine to push for a return to the White House in 2024, arguing that the world had become less safe with Mr Biden as US President.

“For four straight years under the Trump administration, I kept America safe. I kept Israel safe. I kept Ukraine safe and I kept the world safe,” he said.

He also attacked special counsel Jack Smith — who is prosecuting Mr Trump in two of his four criminal cases — calling him “deranged”, “a disgrace to America” and “Trump-hating”, while making a reference to Mr Smith’s family.

“His wife and family despise me much more than he does,” he said, referencing Mr Smith’s wife, Katy Chevigny, who worked as a producer for a Netflix documentary about former first lady Michelle Obama before donating $US2,000 ($3,100) to the Biden 2020 campaign.

Mr Trump’s appearance in New Hampshire comes ahead of a new week of his business fraud civil trial in New York City.

From Monday, the Trump defence team will begin its presentation by calling Donald Trump Jr back to the stand as its first witness as it looks to minimise its financial penalty after being found guilty of widespread fraud by Judge Arthur Engoron.

None of Mr Trump’s state or federal trials have been televised, but the former reality star told the New Hampshire audience that he would like his election subversion trial in Washington, DC — due to start on March 4 next year — to be broadcast live.