Summary: In this paper, we introduce argumentation frameworks with necessities (AFNs), an extension of Dung’s argumentation frameworks (AFs) taking into account a necessity relation as a kind of support relation between arguments (an argument is necessary for another). We redefine the acceptability semantics for these extended frameworks and we show how the necessity relation allows a direct and easy correspondence between a fragment of logic programs (LPs) and AFNs. We introduce then a further generalization of AFNs that extends the necessity relation to deal with sets of arguments. We give a natural adaptation of the acceptability semantics to this new context and show that the generalized frameworks allow to encode arbitrary logic programs.