“It is appalling that a public official in Russia would even propose the death penalty for two American citizens in Ukraine,” National Security Council spokesman John Kirby told a White House spokesman. “We will continue to try to find out what we can do about it,” he added. Alexander Drueke, 39, and Andy Huynh, 27, are believed to be being held by the pro-Moscow Donetsk People’s Republic, which this month sentenced a Moroccan and two British fighters to death. Kremlin spokesman Dmitry Peshkov told NBC on Monday that the couple were “soldiers of luck” entitled to criminal prosecution – before saying in a press conference on Tuesday that Russia “could not rule out” their executions. National Security Council Coordinator John Kirby criticized the announcement that two Americans could be executed after fighting for Ukraine. AFP via Getty Images Dmitry Peshkov refuses to rule out executions of Americans.NBC News “We can not rule out anything, because these are court decisions. “We do not comment on them and we have no right to intervene,” Peshkov said. Drueke and Huynh, both U.S. Army veterans from Alabama, are believed to have been arrested near Kharkiv as they helped Ukraine retaliate against the Russian invasion, which began on February 24. Russia recognizes Donetsk as an independent country, but its rebel leaders have relied heavily on Russia since 2014 for support. Russia does not have the death penalty as a criminal punishment, but the breakaway state has. In a video interview recorded after their arrest, an investigator possibly linked to pro-Russian rebels informed Huynh that he was eligible for the death penalty under the laws of the Donetsk Republic. US veteran Andy Huynh arrested in Ukraine.RU-RTR / Handout via REUTERS TV Alexander Drueke believed to be being held by the Donetsk People’s Republic.RU-RTR / Handout via REUTERS TV “Do you know about the death sentence imposed on the two British soldiers and do you know the realistic probability of your death?” says the person. Huynh responded, possibly under pressure, that “I know I have committed crimes and I am willing to accept my punishment.” British and Moroccan fighters who had previously been sentenced to death by firing squad have not yet been killed.