Donald Trump has suggested he may try to regain control on the Panama Canal after describing the deal to sell the passage to Panama as 'foolish'.
The Canal was ceded to its Central American ally under Jimmy Carter in the 70s.
Trump contends that shippers are charged "ridiculous" fees to pass through the vital transportation channel linking the Atlantic and Pacific Oceans.
The Republican president-elect used his first major rally since winning the White House on November 5 to bask in his return to power as a large audience of conservatives cheered along.
It was a display of party unity at odds with a just-concluded budget fight on Capitol Hill where some Republican legislators openly defied their leader's demands.
Addressing supporters at Turning Point USA's AmericaFest in Arizona, Mr Trump pledged that his "dream team cabinet" would deliver a booming economy, seal US borders and quickly settle wars in Israel and Ukraine.
"I can proudly proclaim that the Golden Age of America is upon us," Mr Trump said.
"There's a spirit that we have now that we didn't have just a short while ago."
His appearance capped a four-day pep rally that drew more than 20,000 activists and projected an image of Republican cohesion despite the past week's turbulence in Washington with Mr Trump pulling strings from his Mar-a-Lago resort in Florida as Congress worked to avoid a government shutdown heading into the Christmas holiday.
House Republicans spiked a bipartisan deal after Mr Trump and Elon Musk, his billionaire ally, expressed their opposition on social media.
Budget hawks flouted Mr Trump's request to raise the nation's debt ceiling, which would have spared some new rounds of the same fight after he takes office on January 20 2025, with Republicans holding narrow control of the House and Senate.
The final agreement did not address the issue and there was no shutdown.
Mr Trump, in his remarks in Phoenix, did not mention the congressional drama, though he did reference Mr Musk's growing power.
To suggestions that "President Trump has ceded the presidency to Elon", Mr Trump made clear: "No, no. That's not happening."
"He's not gonna be president," Mr Trump said.
Mr Trump opened the speech by saying that "we want to try to bring everybody together. We're going to try. We're going to really give it a shot".
Then he suggested Democrats have "lost their confidence" and are "befuddled" after the election but eventually will "come over to our side because we want to have them".
Atop a list of grievances – some old, some new – was the Panama Canal.
"We're being ripped off at the Panama Canal," he said, bemoaning that his country "foolishly gave it away".
The US relinquished control of the waterway to Panama in 1999 under a treaty signed in 1977 under President Jimmy Carter.
Panama's current president, Jose Raul Mulino, is a conservative populist and the country is a strong US ally.
The canal is crucial for Panama's economy and generates about one-fifth of that government's annual revenue.
Mr Mulino was expected to speak about Mr Trump's comments later on Sunday in Panama City.
The canal depends on reservoirs to operate its locks.
It was heavily affected by droughts in Central America in 2023 that forced it to substantially reduce the number of daily slots for crossing ships.
With fewer ships using the canal each day, administrators also increased the fees that all shippers are charged for reserving a slot.
With weather returning to normal in the later months of this year, transit on the canal has normalised.
But price increases are still expected for next year.
Mr Trump said that when he is president "this complete rip-off" of the US "will immediately stop".
If not, he said, the waterway could "be returned to the United States of America in full and without question".
He did not explain how that would be possible.
Mr Trump's appearance at Turning Point's annual gathering affirmed the growing influence the group and its founder, Charlie Kirk, have had in the conservative movement.
Mr Kirk's organisation hired thousands of field organisers across presidential battlegrounds, helping Mr Trump make key gains among infrequent voters and other groups of people that have trended more Democratic in recent decades, including younger voters, black men and Latino men.
"You had Turning Point's grassroots armies," Mr Trump said.
"It's not my victory, it's your victory."
Earlier on Sunday, Mr Trump said that Stephen Miran, who worked at the Treasury Department in Mr Trump's first term, was his choice to lead the Council of Economic Advisers.
And Australian billionaire Anthony Pratt announced he was donating 1.1 million dollars to Mr Trump's inaugural fund to complement the 14 million dollars that he said he had already given to the Make America Great Again Inc super political action committee – making him one of the president-elect's top donors.
Mr Pratt is chairman of Pratt Industries, which uses recycled paper and boxes as a raw material in a process that produces new cardboard.