Las Vegas (AFP) - Donald Trump received a standing ovation at a Republican Party gathering Saturday, even as several possible White House rivals lashed out at his election denialism and insisted it was time to move on from the former US president.

In his first major appearance since announcing his intention to run again in 2024, Trump told the Republican Jewish Coalition in Las Vegas that the party had grown under his leadership.

The 76-year-old falsely insisted once again that the 2020 presidential election -- which he lost -- was rigged, and rejected responsibility for the GOP's poor performance in the November midterms.

In 2020 "we had a really disgraceful election, many millions of votes more than we had in 2016... and the result was, in my opinion, an absolute sham," he told the audience by video link.

"The election as rigged, and it's too bad it was."

Asked about how he could improve the party's appeal to suburban voters, among whom it did badly in this month's midterms, Trump insisted he had a record of picking winners.

"In the midterms, as you've probably heard, I was 222 wins and 16 losses, the press doesn't want to mention that, and the Republican Party got five million more votes than the Democrats," he said, despite the final vote tallies not yet being finalized. 

"The Republican Party is a much bigger and more powerful party than it was before I got there," he said.

Trump was warmly welcomed by the crowd, which had earlier heard from key party figures whose names are often mentioned as possibly 2024 presidential contenders.

Many of them hit out at Trump's grievance-laden style of politicking, which Republican Party operatives have said was to blame for their tepid showing on November 8.

'Joy and a smile'

New Jersey's former governor and one-time Trump confidante Chris Christie said candidate quality had been the issue.

"Donald Trump picked candidates with one criteria. Not electability, not experience, not wisdom, not charisma, not the ability to govern, but 'do you believe the 2020 election was stolen or not?' If you do I endorse you. If you don't I reject you," he said.

"The fact of the matter is the reason we're losing is because Donald Trump has put himself before everybody else."

Chris Sununu, governor of New Hampshire, agreed.

"I got a great policy for the Republican Party. Let's stop supporting crazy unelectable candidates in our primaries," he said.

On Friday evening, Trump's former secretary of state, Mike Pompeo, who is also understood to be mulling a run at the White House, urged fellow Republicans to be more forward-looking and more positive.

While he did not mention his old boss by name, Pompeo made none-too-subtle digs about the need to be doers, rather than complainers.

"As we present the conservative case, as we make the argument... we do so with joy, and a smile," he said.

"We don't simply rail against the machine... we don't simply go on Fox News or send tweets, we actually do the hard work."

Trump did not address the potential rivals in his appearance on Saturday, but has already begun his customary bomb-throwing about potential presidential competitors, dubbing Ron DeSantis, who is set to speak later Saturday, "Ron DeSanctimonious" and saying Virginia Governor Glenn Youngkin's name "sounds Chinese."

The gathering, which also featured an address by Israel's prime minister-designate Benjamin Netanyahu, runs until Sunday.