The problem of constructing universal two-nucleon momentum distributions for main NN-configurations \(^{1}{{S}_{0}}\) and \(^{3}{{S}_{1}}\) – \(^{3}{{D}_{1}}\) used to describe short-range nucleon correlations in nuclei has been studied. A new method for calculating such distributions has been proposed, and their properties have been studied. As illustrations, calculations for several modern realistic NN potentials, including non-nucleon degrees of freedom, have been provided. A new characteristic that determines the ratio of the fractions of high-momentum components for spin-singlet and spin-triplet NN distributions at low energies, which can be useful for comparative evaluation of the isospin dependence of short-range correlations in calculations with different NN interaction potentials, has been proposed.