The Zwanzig-Nakajima projection-operator method is extended to the case of time-dependent nonlinear projection operators. A method employing these operators is proposed for constructing the non-Markovian kinetic equation for a single-particle, time-dependent distribution function. An important assumption is made in the derivation of the equation regarding the factorization of the initial nonequilibrium distribution of the multi-particle system. An approximate kinetic equation is obtained for a slightly nonequilibrium system which asymptotically approaches the equilibrium canonical distribution at a fixed temperature. The effects of the self-consistent Vlasov field and the non-Markovian Fokker-Planck collision operator with a microscopic parameter appear in this equation. This is the first derivation of such an equation.