"Humanitarian diplomacy is persuading decision makers and opinion leaders to act at all times in the interests of vulnerable people, and with full respect for fundamental humanitarian principles.
The rapid expansion of the number of humanitarian actors in recent years, working for or with governments at all levels and often in complex situations, makes humanitarian diplomacy increasingly important.
Humanitarian diplomacy aims to mobilise public and governmental support and resources for humanitarian operations and programmes, and to facilitate effective partnerships for responding to the needs of vulnerable people. Humanitarian diplomacy includes advocacy, negotiation, communication, formal agreements, and other measures. It is a field with many players, including governments, international organisations, NGOs, the private sector, and individuals."
More information in the link: https://www.diplomacy.edu/courses/humanitarian