NEW YORK (AFP) — United States President Donald Trump was booed during the National Basketball Association (NBA) Finals matchup at Madison Square Garden on Monday, as his attendance prompted ultra-tight security at the storied New York venue.

Fans jeered the Republican leader, who was watching the game from an executive suite, when he appeared onscreen inside the arena during the singing of the national anthem.

Security measures were hiked for the visit, with authorities barring fans without tickets from coming within several blocks of Madison Square Garden.

They also banned watch parties directly outside the Manhattan venue — a break from the first two playoff games between the Knicks and the San Antonio Spurs, which drew jubilant crowds.

Officials urged ticket holders to arrive at least two hours before the 8:30 p.m. tip-off to clear airport-style security screening. Bags were not permitted inside.

“The message is simple: celebrate the Knicks but avoid the MSG area tonight if you do not have tickets for the game,” NYPD Commissioner Jessica Tisch told a news conference.

The Spurs edged the Knicks, 115-111, cutting the New York team’s lead to 2-1 in the best-of-seven championship series.

Ahead of the game, AFP journalists saw a 10-foot (three-meter) fence around parts of Madison Square Garden and a large presence of Secret Service personnel charged with protecting the US president.

The agents, some heavily armed, were accompanied by hundreds of NYPD officers as crowds gathered on streets near the venue and at public viewing areas elsewhere in the city.

Some New Yorkers and Democratic lawmakers criticized Trump for the inconvenience.

“During one of the best moments NYC has enjoyed in decades, (Trump) makes it all about himself. Trump should LEAVE US ALONE! He’s not wanted here,” Senate Minority Leader Chuck Schumer wrote on X.

As Trump’s convoy traveled through New York to Madison Square Garden, some protesters on the streets held signs saying “Trump must go.” At least two people raised their middle fingers towards the vehicles.

Knicks fan Anthony Pulley, 43, told AFP he appreciated Trump coming to the game even if he found the disruption annoying.

“I think it sucks. I think it really put a damper on all the watch parties. But it’s pretty cool he wants to show up and be a part of it,” he said.

The Knicks, chasing their first basketball championship since 1973, have whipped up a feverish following in the largest US city.

Ticket prices for Monday’s game were out of reach for most New Yorkers, but the self-proclaimed “World’s Most Famous Arena” was still packed to the rafters, with celebrity fans courtside.

Among those attending was New York Mayor Zohran Mamdani, who told reporters he paid nearly $1,000 for his tickets.

The Secret Service deployed counter-drone technology as part of its operation to protect the US leader, who has faced three alleged assassination attempts in less than two years.

Trump, a long-time Knicks fan and native New Yorker, last visited Madison Square Garden in November 2024 to watch a UFC fight after his election victory. He earlier held a campaign rally at the venue.