Using POST as a workaround for the URL character limit

If you have an API and support the POST operation only because of URL length limitations and the passing of complex parameters in the request, can you still say that you have a RESTful architecture?

What the above basically implies is that for this particular (read-only) API, there is no semantic difference between a GET and a POST, so what can be done with a GET can also be done with a POST (but not vice versa due to the limitations).

Would this still make the style of the architecture a RESTful one?