PALM BEACH, FLA. -- It was supposed to be a unifying weekend for a Republican Party at war with itself over former U.S. President Donald Trump's divisive leadership. But Trump himself shattered two days of relative peace in his closing remarks to the GOP's top donors when he insulted the party's Senate leader and his wife.

Ahead of the invitation-only speech at Trump's new home inside his Mar-a-Lago resort, the former president's advisers said he would emphasize his commitment to his party and Republican unity.

Trump veered sharply from prepared remarks Saturday night and instead slammed Senate Minority Leader Mitch McConnell, R-Ky., as a "stone-cold loser" and mocked McConnell's wife, Elaine Chao, who was Trump's transportation secretary.

Trump also said he was "disappointed" in his vice-president, Mike Pence, and used a profanity in assessing McConnell, according to multiple people in attendance who were not authorized to publicly discuss what was said in a private session. He said McConnell had not thanked him properly for putting Chao, who was labour secretary under President George W. Bush, in his Cabinet.

McConnell's office did not immediately respond to a request for comment Sunday.

Trump's words left some attendees feeling uncomfortable.

Former House Speaker Newt Gingrich did not defend Trump as he left Palm Beach on Sunday.

"We are much better off if we keep focusing on the Democrats. Period," Gingrich said.

Saturday's speech was the final address of the Republican National Committee's weekend donor summit in Palm Beach. Most of the RNC's closed-door gathering was held at a luxury hotel a few miles away from Mar-a-Lago; attendees were bused to Trump's club for his remarks.

While a significant faction of the Republican Party hopes to move past Trump's divisive leadership, the location of the event -- and the former president's prominent speaking slot -- suggests that the GOP, at least for now, is not ready to replace Trump as its undisputed leader and chief fundraiser.

Ahead of his latest attack on fellow Republicans, Trump's team reported that his remarks were intended to reinforce his continued leadership role in Republican affairs, a sharp break from past presidents.

"Saturday's speech will be welcomed words to the Republican donors visiting Mar-a-Lago to hear directly from President Trump," Trump adviser Jason Miller said. "Palm Beach is the new political power centre, and President Trump is the Republican Party's best messenger."

The new tension between Trump and establishment-minded Republican leaders comes as GOP officials are trying to play down an internal feud over his role in the party, his commitment to Republican fundraising and his plans for 2024. Trump is also continuing to insist that the last election was "stolen" from him, repeating false claims that Joe Biden won the election only because of voter fraud.

Such claims ultimately fueled the Jan. 6 attack on the Capitol.

McConnell and Chao have been particularly critical of Trump's role in encouraging the insurrection; Chao resigned her post in protest. Pence, meanwhile, presided over a congressional session that certified Biden's election victory over Trump.

Rep. Liz Cheney, R-Wyo., was among 10 House Republicans who joined every Democrat in voting to impeach Trump for inspiring the Jan. 6 attack. Seven Republican senators later voted to convict Trump, even after he had left office.

"The former president is using the same language that he knows provoked violence on Jan 6. As a party, we need to be focused on the future, we need to be focused on embracing the Constitution, not embracing insurrection," Cheney told CBS' "Face the Nation."

Trump and his allies have already promised to fuel primary challenges against Cheney and those Republicans who supported his impeachment.

And while the Republican National Committee signalled its commitment to Trump by hosting its spring donor summit at his doorstep, Trump's commitment to the GOP is far from certain.

Earlier in the year, he raised the possibility of creating a new political party. Just a month ago, Trump's political action committee sent letters to the RNC and others asking them to "immediately cease and desist the unauthorized use of President Donald J. Trump's name, image, and/or likeness in all fundraising, persuasion, and/or issue speech."

GOP officials saw Trump's weekend participation as a sign that he is willing to lend his name to the party. At the same time, he continues to aggressively accumulate campaign cash to fuel his own political ambitions.

Trump has accumulated a total of roughly $85 million so far, a small fortune that rivals the RNC's bank account. He has teased the prospect of another presidential run in 2024, but has also positioned himself to play the role of kingmaker for Republicans who may run if he does not.

The weekend gathering featured Florida Gov. Ron DeSantis and Arkansas Sen. Tom Cotton, among other early 2024 prospects.

In his remarks Friday night, Cotton leaned into the GOP's culture wars, attacking the Democrats' positions on transgender youth, voter ID laws and Major League Baseball's decision to move its All-Star Game to protest Republican voting laws.

DeSantis, who spoke before Trump on Saturday night, also seized on corporations and business leaders who have begun joining the Democrats' fight against GOP-backed voting legislation moving through state legislatures across the country, including Florida. Critics and voting experts suggest the new laws would make it more difficult for Black Americans and Latinos to cast ballots.

DeSantis specifically warned Saturday that there would be "consequences" for business leaders who pressure lawmakers in Florida as they did in Georgia. But neither DeSantis nor Cotton attacked any fellow Republicans.

Meanwhile, the second-ranking Republican senator, South Dakota's John Thune, gently condemned Trump's attack on McConnell.

"I think a lot of that rhetoric is -- you know, it's part of the style and tone that comes with the former president," Thune said on "Fox News Sunday." "But I think he and Mitch McConnell have a common goal, and that is getting the majority back in 2022. And in the end, hopefully that will be the thing that unites us, because if we want to defeat and succeed against the Democrats and get that majority back, that's the best way to do it."