Confetti falls at midnight on the Times Square New Year's Eve celebration in New York. Photo by Ben Hider/Invision/AP

New York - A massive crowd people watched the traditional ball drop at Times Square on New Year's Eve to welcome in 2020 on the east coast of the United States.

Around one million people packed into an area of several blocks around Midtown Manhattan to ring in 2020. Millions more watched various television shows broadcast from the venue.

The revellers sang "Auld Lang Syne" and "New York, New York" once the ball had dropped and the new year had officially begun.

Security was tight, as also in recent years.

"Coming to Times Square to watch the ball drop? Expect to see a large police presence, including our highly trained NYPD Counterterrorism Bureau, as we ensure the safety of everyone attending tonight's event," the New York Police Department said in a tweet.

The city traditionally hosts several New Year's Eve shows and is considered the epicentre of US New Year's Eve celebrations.

People started showing up Tuesday morning to get a place on or around Times Square.

Live shows by the major television networks culminate with a countdown to the ball drop.

This year's line-up included Dick Clark's New Year's Rockin' Eve With Ryan Seacrest. The production, which has been broadcast from Times Square for decades, includes performances by performers including Kelsea Ballerini, Green Day, Jonas Brothers, Sheryl Crow, Alanis Morissette and Post Malone.

Shania Twain, Christina Aguilera, Lenny Kravitz and 50 Cent headline CNN's programme. On Fox, the Village People aim to host the world's biggest choreographed "YMCA" dance and will feature performances by The Chainsmokers, the Lumineers, the Backstreet Boys and Florida Georgia Line.

Party-goers in Times Square saw a shower of confetti in the night sky as the clock ticked over to the start of 2020.

BTS performs at the Times Square New Year's Eve celebration in New York. Photo by Ben Hider/Invision/AP

In a tradition started last year, some of the bits of fluttering paper included the hand-written wishes of people from around the world.

The iconic New York City ball is an illuminated sphere constructed of 2,688 Waterford Crystal triangles. It is about 4 metres in diameter.

Sam Hunt performs at the Times Square New Year's Eve celebration in New York. Photo by Ben Hider/Invision/AP

Among the other New Year"s Eve highlights in the Big Apple were a fireworks display and a run through Central Park.

US cities that don't have a ball or confetti have come up with other novel items to lower slowly as they mark the start of the new year.

In the US country music mecca Nashville, Tennessee, the new year will be celebrated by a 5-metre tall music note made up of 13,000 LED lights lowered from a tower in a state park.

There also are some wacky "drops" for cities that don't have crystal balls.

Post Malone performs during New Year's Eve celebrations in Times Square in the Manhattan borough of New York. Picture: Jeenah Moon/Reuters

Lebanon, Pennsylvania, drops a giant bologna sausage, while Vincennes, Indiana, has a massive watermelon drop, and Key West, Florida, has the lowering of a drag queen in an oversized red shoe.