Keep in touch is a request not to lose contact. Do keep in touch, we must keep in touch.
It is sincere at a leaving do and hollow at the end of an interview, where it often means no. It is an instruction in form and a hope in fact.
1phrasekeep in touchA request not to lose contact.
“She made him promise to keep in touch.”
keep in touch is a phrase.
Practised in Small Talk & Everyday Phrases