K-Pop has officially arrived in America, thanks to the recent popularity of groups like Girls' Generation and 2NE1.

Korean pop music has been spreading so far and wide that in 2011, Billboard launched its very own Korea K-Pop Hot 100 chart.

With YouTube numbers reaching Justin Bieber and Lady Gaga levels, K-Pop groups are beginning to pick up traction in America.

But the phenomenon is nothing new outside of the US. In the last decade or so, K-Pop has dominated music charts in Japan, Southeast Asia, the Middle East, Latin America and beyond.

In May 2011, thousands of K-Pop fans held a nasty protest outside the Louvre in Paris, after a show (dubbed Europe's first K-Pop concert) had sold out.

Major news organizations have also jumped on the K-Pop train. Just last week, Al Jazeera's 101 East presented a 25-minute documentary titled, South Korea's Pop Wave.

On Tuesday, David Letterman welcomed all nine members of Girls' Generation on The Late Show (see video below). Making their US TV debut, the group performed their hit single The Boys, which debuted at number one in Korea back in October. The Korean version of the song also debuted on top of the Billboard K-Pop Hot 100.

The girl group returned to US TV stations the very next day, with an appearance on Live! with Kelly.

In 2012, expect more US headlines about K-Pop acts like Girls' Generation, Wonder Girls and the all-male group BEAST, who will embark on a 21-city world tour this month.

Click through for a list of K-Pop super stars expected to make a lot of noise in America this year.

What other K-Pop acts are you excited about this year? Share your thoughts below.

Girls Generation
The top Korean girl band. Three studio albums. The record holder for the longest number one song on KBS Music Bank, a top-rated South Korean music channel. With these credits behind them, all nine members of Girls’ Generation made their US television debut on Tuesday, as the musical guest on “The Late Show with David Letterman.”“Look, the girls are here everybody!” shouted an ecstatic Letterman after the performance.Since forming in 2007, Girls’ Generation has released music in Korean, Japanese and for the first time in their career, English (with “The Boys” in 2011). REUTERS
2NE1
Hip-hop girl group 2NE1’s most watched YouTube video, “I Am The Best,” has received more than 31 million views since its premiere some seven months ago.The group’s popularity spread so fast that in December 2011, MTV Iggy (an international MTV new music site) crowned 2NE1 the Best New Band in the World (based on fan votes). The network also flew the band into New York City to headline a show in Times Square, along with acts from Venezuela, Jamaica and Malaysia. REUTERS
Michael B. Jordan 7 Things You Maybe Didnt Know About Peoples Sexiest Man Alive 2020
Michael B. Jordan: 7 Things You Maybe Didn’t Know About People’s Sexiest Man Alive 2020
BEAST
BEAST (also known as B2ST) can dance. BEAST can sing. And BEAST is about to embark on a 21-city world tour this month, with stops in London, New York, Vancouver, Singapore, Thailand and the Philippines.The group has also been quite popular in the fashion world, receiving praise from American designer Patricia Field.Just last week, BEAST unleashed its first digital single, “I Knew It.” REUTERS
IU
IU, whose real name is Lee Ji-eun, is in a category of her own. The singer-songwriter has been making quite a splash in the K-Pop world since her debut four years ago.In its nine weeks of charting, IU’s latest single “You and I” spent five consecutive weeks on top of Billboard’s K-Pop Hot 100 chart (this week the single sits at number five).In her career so far, IU has performed with British musician Corinne Bailey Rae, signed endorsement deals with Samsung, Mexicana Chicken and clothing line UNIONBAY.Not too shabby for an 18-year-old. REUTERS
Japan Billboard Lady Gaga Justin Bieber