Russia said the two Americans arrested in Ukraine would not be bound by Geneva Prisoner of War Convention laws, explaining that the two were in Ukraine to make money.
The two soldiers, identified as Alexander Drueke, 39, and Andy Huynh, 27, were captured by Russian-backed separatists in Ukraine's Donbas region.
Her whereabouts are unknown. Both men are believed to be from Alabama and registered with the Ukrainian military.
However, Russia calls them mercenaries and has been sentenced to death.
Responding to U.S. demands to treat captured Americans as prisoners of war under the Geneva Conventions (fair trial, prohibition of torture, prohibition of food and health care), Kremlin spokesman Dmitry Peskov said the two Americans committed crimes
Fighting with Russian troops in Ukraine.
Peskov said two U.S. soldiers were involved in the "shooting and shelling of our personnel," while declaring that "these crimes must be investigated."
A Kremlin spokesman said the prisoners would not be bound by the Geneva Conventions, while calling them "lucky soldiers". They do not belong to the Ukrainian army, Peskov said.
"The only thing that is clear is that they committed a crime. You are not in the Ukrainian army. They are not bound by the Geneva Conventions," Peskov said.
State Department spokesman Ned Price called on Russia to treat captured soldiers as "prisoners of war under the Geneva Conventions."
"Prisoners of war must be treated and protected commensurate with their status, including humane treatment and basic due process and safeguards," Price added.
Russia last week sentenced two Britons and a Moroccan to death in a separatist court in Donetsk, calling them mercenaries.
