How to retrieve files from a drive needed to be re-formatted?

I have a portable drive that has some files in it. Somehow all of a sudden the files in there are not visible or retrievable. Connecting it to a computer USB port, I can only see a message saying the drive needs to be formatted.

If I follow the prompt to format it, I can imagine I would lose all the files in there. Is there any way I can go around it? I wonder!