"We consider such actions by the Ukrainian security bodies against Russian citizens as another flagrant provocation and demand their immediate return to Russia," a statement by the ministry's press service said.
The ministry said on Monday that the two soldiers were kidnapped on November 20, and taken across the border to the Nikolayev region of Ukraine with an apparent goal of pressing charges against them. They also expressed concern that authorities may use psychological and physical torture to coerce the two men into falsely confessing to crimes against Ukraine.
Russia's historical southern region of Crimea rejoined the country after a 2014 referendum. Nearly 97 percent of the region's population voted for reunification in a referendum.