Donald Trump encountered a mortifying welcome as fans mercilessly jeered him upon his entrance at Game 3 of the NBA Finals on Monday evening at New York City's iconic Madison Square Garden.

The president endured a barrage of hostility as the audience heckled his motorcade. Numerous onlookers displayed placards expressing their disdain for the president, with at least two individuals making vulgar hand signals towards him, while another offered him a thumbs down.

"Put them gas prices down!" one supporter can be heard yelling before launching an expletive at Trump. "F--- Trump, but we came here for the Knicks!" another can be heard crying out. The gathering around them can be heard chanting, "F--- Trump, go Knicks!"

According to Jeff Mordock, a Washington Times correspondent in Trump's press pool, one placard read, "Nobody wants you here." Another stated, "Trump must go." Yet another declared, "Impeach. Convict. Remove."

Security measures ahead of Trump's appearance at the legendary Manhattan arena, home to the New York Knickerbockers - more commonly known as the Knicks - had already left basketball enthusiasts and New Yorkers feeling uneasy.

Secret Service operatives were observed vetting supporters as they entered the stadium. Earlier that day, it had been confirmed that supporters would be prohibited from bringing bags into the arena, even those conforming to its standard requirements, owing to the president's scheduled attendance. Outside the venue, officers were seen directing crowds into cordoned-off queues, which stretched considerably before the opening tip. Footage showed fans waiting in excess of an hour to gain entry, where they were subsequently met with heightened security measures from the Secret Service.

Video captured from the nearby waterfront revealed large military helicopters positioned on platforms close to the shoreline, with smaller aircraft circling above, scanning for potential threats.

Trump confirmed he would be present for Game 3 of the Finals, which sees the Knicks host the San Antonio Spurs in their first home fixture of the best-of-seven series.

Having claimed victory in the opening two matches, the Knicks require just two further wins to be crowned NBA champions for the first time since 1973.

The Spurs, meanwhile, must secure four victories to claim the franchise's sixth NBA title since 1999, the year both sides last faced each other in the Finals.