'Gangnam Style' star Psy didn't expect his hit song to be so "tremendously" successful.

The eccentric singer stormed to the top of the international charts with his catchy Korean tune which is accompanied by a humorous dance performance.

'Gangnam Style' broke records today by becoming the first video to reach one billion views on YouTube.

Psy is astounded by its popularity.

He gushed to MTV News: "I can't compare it to anything else! In 2012, I experienced so many things; it's been a tremendous year, but to accomplish this, it's really something that stands out. Because it all began with YouTube, and to have [the video] reach one billion views... I don't think even I can break that record!

He added: "Honestly, when I made this video I didn't even expect one million views, because this is off my sixth album in Korea, so I just hoped it would be huge there. I didn't even think about any other countries; I just did my job and waited and watched. And, you know, today, I'm still wondering and analysing its success. Because I've done this thing many times, this dance, this album, this video ... this one just became something else entirely."

The previous most-watched clip on YouTube was Justin Bieber's video for his song 'Baby'.