Noncooperative games in normal form and in characteristic function form are considered. The supergame of the noncooperative game is defined as an infinite sequence of plays of the original game. The notions of strong Pareto equilibrium point (s.p.e.p.) and essential core are introduced. A relationship between the essential core of a noncooperative game and the set of s.p.e.p. of its supergame is asserted. This result is similar to that ofAumann for cooperative games without side payments.