Hi,
Our support for AVR devices is somewhat basic as they are much less popular than ARM-based devices like STM32.
VisualGDB actually relies on an open-source tool called AVaRICE in order to handle the low-level communications. According to this thread, AVaRICE should be able to support Atmel ICE, although we have not tested it explicitly and cannot guarantee it. We would recommend experimenting with the AVaRICE command line to see if it gets to work.
If you encounter any problems, feel free to post the details here and we will try to help, but unfortunately we cannot give a 100% guarantee that Atmel ICE will work.