Hi Esteban,
I think there is no problem with citizenship - on some forms that need to be filled when you start training I saw a place where they mention foreign applicants and that they need valid passport.
But try contacting CAA in Slovakia - department of licensing - phone 00421 2
48 77 75 58 and ask them directly. Or if you can speak Slovak, you can try their web - www.caa.sk.
I hope this helps a bit.
Yames