Chaotic scenes erupted at Miami's Hard Rock Stadium on Sunday as thousands of fans were kept waiting outside the venue ahead of the Copa America final between Argentina and Colombia.

Tournament organisers halted entry into the ground and delayed kick-off of the South American football showpiece by 30 minutes after throngs of fans were kept waiting at entry gates.

A statement by Copa America organisers on X, formerly Twitter, appeared to suggest the chaos had been caused by unticketed fans attempting to gain entry.

"Please be advised that people who do not have tickets will not be able to enter the stadium," the statement said. 

"Only those who have purchased tickets will be able to enter once access is reopened.

"The match will be postponed for 30 minutes, starting at 8.30pm local time (0030 GMT)."

Police and security staff clashed with supporters who tried to enter the ground before kick off.

An AFP reporter on the scene witnessed several fans receiving treatment from paramedics inside the venue.

Miami Dade Police said in a statement there had been "several incidents" prior to the game at the venue.

"These incidents have been a result of unruly behavior of fans trying to access the stadium," the statement said.

"We are asking everyone to be patient and abide by the rules set by our officers ... unruly behavior will get you ejected and/or arrested. We have a zero tolerance behavior against unruly conduct from everyone attending."

Fans however took aim at the organisation of he event, with one Argentina supporter saying fans had been treated like "animals."

"They are treating us like animals, basically there's no organisation whatsoever, there is nothing. I mean, they didn't prepare for 60,000 people," Cabarelli said. "There is no preparation, people are fainting and passing out."

Asked if the situation had felt dangerous, Cabarelli said: "100 percent. I'm still  shaking. I feel like I'm a cow."

Other fans interviewed by AFP  described chaotic scenes at the entrance gates, with some fans forcing their way into the venue past security staff as frustration boiled over.

"It was crazy, people were just trying to get in like crazy," said David Fernandez, a Colombia fan from Gainesville, Florida.

"They just didn't want to wait. They were just rushing over and running over. They've opened the gates three different times -- it was good for two or three minutes and then everybody was just rushing."

Rosy Riales said fans lining up in sweltering temperatures had got increasingly frustrated at the failure to open the gates on time. 

"People are just riled up and excited, so they're pushing and it's like mayhem," she told AFP. "They should have opened the gates sooner to let people in slowly."

The chaos comes amid heightened scrutiny of stadium security at the Copa America following a brawl which marred the end of Wednesday's semi-final between Colombia and Uruguay.

Uruguayan players climbed into the stands and clashed with Colombian fans, claiming family members had been threatened in the aftermath of Uruguay's 1-0 defeat.