Without a Modchip, they probably won't work. The Wii Games form USA are NTSC-U, the Wii Games from Asia are NTSC-J and the Wii Games from Europe/Australia are PAL.
You can only play Wii Games on their depending Wii. So, for example a NTSC-U game will only work on an American Wii ( a NTSC-U Wii as you should be able to conclude) and a PAL Game will only play on a Wii from Australia or Europe.
If you want to play games from a different region on your Wii, you have to install a modchip which is capable of playing Wii Games from different regions. But Actually, they're most likely used to play pirated games from the internet. Yarr!