We show that every finite-dimensional p-adic Lie group of class Ck (where k ∈ ℕ ∪ {∞}) admits a Ck-compatible analytic Lie group structure. We also construct an exponential map for every k + 1 times strictly differentiable (SCk+1) ultrametric p-adic Banach-Lie group, which is an SC1-diffeomorphism and admits Taylor expansions of all finite orders ≤ k.