  A structural orthorhombic-to-tetragonal phase transition was recently
discovered in the heavy-fermion compound UTe$_2$ at a pressure
$p^*\simeq3-8$~GPa [Honda \textit{et al.}, J. Phys. Soc. Jpn. \textbf{92},
044702 (2023); Huston \textit{et al.}, Phys. Rev. Mat. \textbf{6}, 114801
(2022)]. In the high-pressure tetragonal phase, a phase transition at
$T_x=235$~K and a superconducting transition at $T_{sc}=2$~K have been
revealed. In this work, we present an electrical-resistivity study of UTe$_2$
in pulsed magnetic fields up to $\mu_0H=58$~T combined with pressures up to $p$
= 6 GPa. The field was applied in a direction tilted by 30~$^\circ$~from
\textbf{b} to \textbf{c} in the orthogonal structure, which is identified as
the direction \textbf{c} of the tetragonal structure. In the tetragonal phase,
the presence of superconductivity is confirmed and signatures of metamagnetic
transitions are observed at the fields $\mu_0H_{x1}=24$~T and
$\mu_0H_{x2}=34$~T and temperatures smaller than $T_x$. We discuss the effects
of uniaxial pressure and we propose that a magnetic ordering drives the
transition at $T_x$.
