In this paper, we study weak and strong transience of a class of Feller processes associated with pseudo-differential operators, the so-called Lévy-type processes. As a main result, we derive Chung-Fuchs type conditions (in terms of the symbol of the corresponding pseudo-differential operator) for these properties, which are sharp for Lévy processes. Also, as a consequence, we discuss the weak and strong transience with respect to the dimension of the state space and Pruitt indices, thus generalizing some well-known results related to elliptic diffusion and stable Lévy processes. Finally, in the case when the symbol is radial (in the co-variable) we provide conditions for the weak and strong transience in terms of the Lévy measures.for a (transient) Lévy process {L t } t≥0 and any κ > 0, E[L κ B(0,r) ] is either finite or infinite for every r > 0 (see also [Haw77] for the case of symmetric Lévy processes). Accordingly, a (transient) Lévy process {L t } t≥0 is said to be κ-weakly transient if E[L κ B(0,r) ] = ∞ for all r > 0, and κ-strongly transient if E[L κ B(0,r) ] < ∞ for all r > 0. Also, in the same reference, the authors have proved that the above conditions are equivalent to ∞ 0 t κ P(L t ∈ B(0, r))dt = ∞ for all r > 0 and ∞ 0