Every PS2 is region locked. There are several regions, such as region 1, region 2, etc. I'm kinda an idiot I can't even remember which number refers to which region... I think region 1 is US, region 2 is Europe, etc.
Anyways, to the point, like I said every PS2 is region locked. It cannot play content that is from outside of the country/region the PS2 is from.
If you have an American PS2, it will not play Asian or European DVDs. Try putting the DVD onto your laptop, it might have to ask you to switch your region for the DVD to play correctly, it'll list all the regions.
The PS3 is totally region free, as far as I'm aware. PS2 is still old school region locked though, unfortunately. Did not work when I tried to play my Kung Fu Hustle DVD.