Kind of. On the 4, instead of just placing the right foot back into position like you would in mambo, you do actually step to the side. You need do something else to use up all the extra time you have in int rumba (it's generally slower than American). If you think about it, cha cha is the same thing. It's just you have a syncopated step between the forward and back basic.
Bolero has the same footwork as well, except there's a long swaying side step instead of the syncopated step. In some ways, you should think of int rumba as being closer to bolero than American rumba.