Local Minkowski units in non-abelian extensions with cyclic Sylow $p$-subgroups

We establish a criterion for the existence of a local Minkowski unit at $p$ that applies to all Galois extensions with Galois group isomorphic to the direct product of a non-$p$-group and a cyclic $p$-group. As applications, we construct non-abelian extensions admitting a local Minkowski unit at $p$ under various ramification conditions and analyze the Iwasawa module structure of units in ${\mathbb{Z}}_p$-extensions of number fields. We also extend our study to the case where the group of $p$-power roots of unity is nontrivial.