US President Donald Trump has endorsed Andrew Cuomo in the New York City mayor's race, urging voters not to elect left-wing front-runner Zohran Mamdani.

"Whether you personally like Andrew Cuomo or not, you really have no choice. You must vote for him, and hope he does a fantastic job," Trump posted on Truth Social Monday evening. "He is capable of it, Mamdani is not!"

The tepid endorsement of the former New York governor comes on the eve of the highly-watched mayoral election.

On Sunday, the president said he would be reluctant to send federal funding to his hometown of New York if Mamdani is elected.

"It's gonna be hard for me as the president to give a lot of money to New York, because if you have a Communist running New York, all you're doing is wasting the money you're sending there," Trump said in a television interview.

Opinion polls indicate Mamdani, the Democratic nominee, is ahead of Cuomo, who is running as an Independent after Mamdani bested him in the Democratic primary. The Republican candidate, Curtis Sliwa, trails behind.

Trump, also a Republican, declined to endorse Sliwa in his post, saying "A vote for Curtis Sliwa ... is a vote for Mamdani".

On federal funding, the president added "it is highly unlikely that I will be contributing Federal Funds, other than the very minimum as required" if Mamdani is elected.

The Trump administration has repeatedly tried to cut federal grants and funding for projects primarily located in Democratic-run areas. New York City received $7.4bn (£5.7bn) in federal funding this fiscal year.

In a wide-ranging interview with CBS programme 60 Minutes on Sunday, Trump said that a Mayor Mamdani would make left-wing former New York City Mayor Bill de Blasio "look great".

"I got to see de Blasio, how bad a mayor he was, and this man will do a worse job than de Blasio by far," the president said of Mamdani.

Trump grew up in the New York borough of Queens and still owns property in the city.

"I'm not a fan of Cuomo one way or the other, but if it's gonna be between a bad Democrat and a Communist, I'm gonna pick the bad Democrat all the time, to be honest with you," the Republican president told CBS.

Mamdani, who would run a world financial hub, is a self-described democratic socialist, though he has rejected accusations he is a communist, joking in one television interview that he was "kind of like a Scandinavian politician", only browner.

Mamdani won the Democratic primary, while Cuomo came second. The 34-year-old state assemblyman has called the former New York governor a puppet and parrot of Trump.

"The answer to a Donald Trump presidency is not to create its mirror image here in City Hall," Mamdani said on Monday.

"It is to create an alternative that can speak to what New Yorkers are so desperate to see in their own city and what they find in themselves and their neighbours every day - a city that believes in the dignity of everyone who calls this place home."

Cuomo has sought to parry that line of attack by presenting himself as the only candidate experienced enough to deal with the Trump administration.

He was governor of New York during the COVID-19 pandemic when many states clashed with the Trump administration, though Cuomo himself came under scrutiny after state investigators found nursing home deaths were significantly understated during the outbreak.

"I fought Donald Trump," Cuomo said during a debate. "When I'm fighting for New York, I am not going to stop."

Trump has deployed National Guard troops to Democratic-led cities as part of a crime crackdown, while seeking to strip funding from jurisdictions that limit their cooperation with federal immigration authorities.