  An M/string-theory origin for the six-dimensional Salam-Sezgin chiral gauged
supergravity is obtained, by embedding it as a consistent Pauli-type reduction
of type I or heterotic supergravity on the non-compact hyperboloid ${\cal
H}^{2,2}$ times $S^1$. We can also obtain embeddings of larger, non-chiral,
gauged supergravities in six dimensions, whose consistent truncation yields the
Salam-Sezgin theory. The lift of the Salam-Sezgin (Minkowski)$_4\times S^2$
ground state to ten dimensions is asymptotic at large distances to the
near-horizon geometry of the NS5-brane.
