If you moved the photos outside Lightroom, it doesn't know that they're moved and thinks they're new files, needing import. If they were in Lightroom, you need to click on the ? on a file and use the dialog to reconnect the missing file.
Another option is to move the files back, and then move them inside Lightroom.
It sounds like you don’t really understand the relationship between the Lightroom catalog and your image files. Here are a couple short articles I wrote about moving folders, and fixing broken links that might help.
Please clarify a few things.
When you did the drag and drop, did you do this in Lightroom, or in your operating system?
When it is asking you to import the photos — what is asking you? what are the exact words?
Have these photos already been imported into Lightroom before you did the drag and drop?
Thanks for replying to this email everyone. Feeling like I need to hide somewhere now. I don't know why but the control panel with Library, Develop, Map, Book, Slideshow etc was missing and all I could see was an import button at the bottom left of the screen. Somehow the control pane was closed down. Didn't know the option was there to do that and somehow LR automatically did.
When I opened it, I see that I can take my photos that I moved to my external drive and edit them in Develop and they have all their info with them. Phew! I will continue to study up more on LR and their catalog system etc.
Thanks for your time