The military was abducted near the administrative border with Crimea / Photo from UNIAN

"We are disturbed by recent media reports that a member of the Ukrainian military was detained by Russian forces on sovereign Ukrainian territory," the embassy said on Twitter on June 3.

"Russia must cease its unlawful occupation of Crimea and halt its aggression in the Donbas. #CrimeaIsUkraine," the tweet said.

Read alsoRussia's FSB confirms detention of Ukrainian serviceman close to Crimea border

As UNIAN reported earlier, a member of Ukraine's Armed Forces was reportedly abducted near the administrative border with Russia-occupied Crimea on May 30. Evidence of a fight with unidentified persons was found not far from his observation post, the Ukrainian military police reported. It became known later that he was remanded in custody on the occupied peninsula.

The Russian Federal Security Service (FSB) then confirmed the detention of the Ukrainian serviceman, having accused him of "illegal border crossing."