I/O Device Error when copying from External Drive

I am trying to copy some files from an external hard drive to another drive. It copies very slowly and then after copying a few files, it gives me the following message “Cannot Copy [filename]: The request could not be performed because of an I/O device error.”

I tried some file recovery programs, but I receive similar messages.

What can I do to recover or copy files from the external hard drive?

Any suggestions are appreciated!