The continuous release of new and increasingly powerful language models is opening possibilities to address applicative scenarios that were not even imaginable a few years ago. In particular, the goal of this PhD is to improve strategic and tactical communication activities during crisis events, through the use of advanced natural language generation and persuasive communication techniques. More specifically, the idea is to directly intervene with textual responses and narratives that are meant to address the public during and after crisis events and natural disasters. To this end the candidate should focus on all those aspects of the LLM, such as decoding strategies, knowledge guided generation, data quality, knowledge distillation, reinforcement learning from human feedback -just to mention a few- that can help in improving the models, especially for better factuality, reducing hallucination and increasing coherence among messages while assisting professionals in crisis management.