Of course, if additional information is needed, please contact me. Follow-up with a letter at a later date if you really want to work at the company. Many new hires are either no-shows or do not work out. Close with another statement about your qualifications. Lastly, ask to be kept in mind if any further openings occur.
Interviewers are usually sensitive and frequently bring up the issue.
When they don't, I suggest you mention it after getting the offer but before accepting. Timing is so important and this should be a matter subject to negotiation and therefore should be included with the final job offer.