R iconv () error - unsupported conversion from 'latin1' to 'ASCII'

I have tried the following code in R

iconv("123", "latin1", "ASCII") 

      

        
        
        
      

    

and get the following error:

Unsupported conversion from 'latin1' to 'ASCII'.

If I try to convert from "UTF-8" to "ASCII" then that's ok.

How to solve a problem?