Children of spies only discovered they were Russian on the plane to Moscow

Among the first prisoners stepping off the plane to greet President Putin was a slender brown-haired woman grasping the hand of her young daughter. She appeared to stifle a sob as she hugged Putin. He handed her a bouquet of pink flowers, and another to her daughter. Putin also hugged her husband and kissed their son.

Then, over the din of the airplane, Putin could be heard greeting the children with "buenas noches" — the Spanish phrase for "good evening."

Their parents were undercover Russian spies who posed as Argentinian citizens living in Slovenia and went by the names Ludwig Gisch and Maria Rosa Mayer Muños. They were part of Thursday's massive prisoner swap involving several countries.

"Before that, they did not know that they were Russian, that they had anything to do with our country," Peskov said in a statement on Friday.

"They asked their parents yesterday who this guy was meeting them, they didn't even know who Putin was," Peskov said, before praising intelligence officers who "make such sacrifices for the sake of their work, for the sake of devotion to the cause."