We study phase transitions in uniformly frustrated SU(N)-symmetric $(2+epsilon)$-dimensional lattice models describing type-II superconductors near the upper critical magnetic field $H_{c2}(T)$. The low-temperature renormalization-group approach is employed for calculating the beta-function $beta(T,f)$ with $f$ an arbitrary rational magnetic frustration. The phase-boundary line $H_{c2}(T)$ is the ultraviolet-stable fixed point found from the equation $beta(T,f)=0$, the corresponding critical exponents being identical to those of the non-frustrated continuum system. The critical properties of the SU(N)-symmetric complex Ginzburg-Landau (GL) model are then examined in $(4+epsilon)$ dimensions. The possibility of a continuous phase transition into the mixed state in such a model is suggested.
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