pep talk 
noun informal
A talk intended to make someone feel more courageous or enthusiastic: I was to meet my editor for a pep talk...
- After the service, he rose to give the soldiers a pep talk and discuss the next morning's mission.
- The Minister has never missed the chance to give a pep talk to the heads of district administration on development projects at such conferences.
- The visit is seen locally as a preliminary pep talk for the Local Elections next year and he will endeavour to rally all the members for those elections.