US president Donald Trump has received a largely negative reaction amid an appearance at an NBA Finals game that saw security ramped up in New York City.

Madison Square Garden was full to the brim for the Tuesday morning (WA time) tip-off of Game 3 between New York and San Antonio, and the president’s presence added to the intense atmosphere.

Trump was largely booed and jeered as he was shown on the big screens during the anthem, saluting with his hand held against his head.

Trump’s presence at the game saw security protocols tightened in a way rarely seen for a sporting event.

Fans were asked to get to the game two hours early and show their tickets at various checkpoints while passing through security scanners.

Bags were not permitted and supporters were not allowed watch parties outside the arena as in previous games across the playoffs, with a multi-block security perimeter in place around the venue.

The usual assortment of big-name celebrities were sitting close to the court in New York, including actors Timothee Chalamet and Ben Stiller and music legend Jay-Z.

The Knicks entered the game holding a 2-0 lead in the best-of-seven series as they hunt their first NBA title since 1973.

More to come