US President Donald Trump said that he had a "very productive meeting" with New York City's mayor-elect Zohran Mamdani.
"We've just had a great ... very productive meeting. We have one thing in common. We want this city of ours that we love to do very well," Mr Trump said in the Oval Office.
"The better he does, the happier I am ... And we're going to be helping him to make everybody's dream come true," Mr Trump said.
"I want to congratulate the mayor, he really ran an incredible race against some very tough people, very smart people."
Earlier, Mr Trump predicted he would "get along fine" with Mr Mamdani.
A democratic socialist and little-known state politician who won New York's mayoral race earlier this month, Mr Mamdani requested the sit-down with Mr Trump, to discuss cost-of-living issues and public safety.
Watch: Trump says he had a productive meeting with Mamdani
The Republican president has issued threats to strip federal funding from the biggest US city, while the mayor-elect has regularly criticised a range of Mr Trump's policies, including plans to ramp up federal immigration enforcement efforts in New York City, where four in ten residents are foreign-born.
The 79-year-old president, a former New York resident, has labelled Mr Mamdani, 34, as a "radical left lunatic," a communist and "Jew hater," without offering evidence for those assertions.
Mr Trump tempered his language as the meeting drew near, saying he expected it to be "quite civil" and commending Mr Mamdani for a "successful run."
"I was hitting him a little hard," Mr Trump told "The Brian Kilmeade Show" on Fox News.
"I think we'll get along fine. Look, we're looking for the same thing: we want to make New York strong."
Mr Mamdani posted a grinning selfie on social media, taken in the seat of a plane bound for Washington.
Watch: Trump says it's ok for Mamdani to call him a 'fascist'
Mr Trump's Oval Office meetings have been wildly unpredictable, including respectful encounters with opponents and ambushes of guests, such as Ukrainian President Volodymyr Zelensky and South Africa's Cyril Ramaphosa.
Mr Mamdani, who will be sworn in as mayor on 1 January, said at a press conference yesterday he had "many disagreements with the president".
"I intend to make it clear to President Trump that I will work with him on any agenda that benefits New Yorkers," he told reporters outside New York's City Hall.
"If an agenda hurts New Yorkers, I will also be the first to say so."
Mamdani's success generate debate among Trump's opponents
Uganda-born Mr Mamdani will be the first Muslim and first South Asian mayor in the city that is home to Wall Street.
His energetic, social media-savvy campaign provoked debate about the best path for Democrats.
Out of power in Washington and divided ideologically, Democrats are mainly unified by their opposition to Mr Trump, who is constitutionally prohibited from seeking another term in 2028.
Mr Mamdani vowed to focus on affordability issues, including the cost of housing, groceries, childcare and buses in a city of 8.5 million people.
New Yorkers pay nearly double the average rent nationwide.
Inflation has been a major issue for Americans, and it is one on which they give Mr Trump low marks.
Just 26% of Americans say Mr Trump is doing a good job at managing the cost of living, according to a Reuters/Ipsos poll this week.
The US federal government is providing $7.4 billion to New York City in fiscal year 2026, or about 6.4% of the city's total spending, according to a New York State Comptroller report.
It was not clear what legal authority Mr Trump could claim for withholding any funding mandated by Congress.
The two leaders traded barbs after the election.
"If anyone can show a nation betrayed by Donald Trump how to defeat him, it is the city that gave rise to him," Mr Mamdani told supporters in his victory speech, which called for Mr Trump to "turn the volume up."
Mr Trump said he was puzzled by Mr Mamdani's speech after excerpts were replayed to him during the Fox News interview this morning.
"I don't know exactly what he means by 'turning the volume up.' He has to be careful when he says that to me," Mr Trump said.
"He was very nice in calling, as you know, and we're going to have a meeting."
