The children of the two Russian agents, who were returned to Russia as part of a major prisoner exchange discovered their nationality only when they arrived in Moscow, the Kremlin announced on Friday.

Their parents, Artem Dulchev and Anna Dulcheva, he was among 24 prisoners exchanged as part of the deal that included the release of American prisoners and Russian dissidents.

The pair posed as Argentines in Slovenia where they were convicted of espionage. Their two children returned with them on Thursday via Turkey.

Boy and girl ‘only found out they were Russian when the plane took off from Ankara’Kremlin spokesman Dmitry Peskov told reporters.

Russian President Vladimir Putin greeted them during their reception in Spanish as they did not speak Russian and did not even know who Putin was, according to Peskov.

“When the children got off the plane because they didn’t speak Russian, Putin greeted them in Spanish, saying ‘Buenas noches,'” Peskov said. “They asked their parents yesterday who he was as they didn’t even know who Putin was.”

After stepping off the plane, Dulcheva tearfully hugged Putin, who stood on the red carpet holding flowers. Putin kissed Dulcheva on the cheek and shoulder and gave her and her daughter the bouquets.

Putin briefly hugged Dulchev and then the rest of the Russians, who were freed.

Thursday’s massive exchange was the result of complex behind-the-scenes negotiations involving the US, Russia, Belarus and Germany that eventually led Berlin to agree to Moscow’s key demand, the release of convicted Russian assassin Vadim Krashikov.

A total of eight people, including Krashikov, were returned to Russia in exchange for the release of 16 people held in Russia, including former US Marine Paul Whelan, Wall Street Journal reporter Evan Gershkovich and two other Americans.

Dulcev and Dulceva pleaded guilty to espionage in a court in Ljubljana on Wednesday and were sentenced to prison terms.

While living undercover in Slovenia, Dulchev pretended to be an IT entrepreneur named Ludwig Gies. After pleading guilty, he was sentenced to more than a year and a half in prison, which the court said was the equivalent of one year. He was ordered deported to Russia and banned from entering Slovenia for five years.

Dulceva lived in Slovenia as an art dealer and gallerist under the name Maria Rosa Mayer Munos. It had also been decided to deport him.

During the conversation with reporters, Peskov also revealed some additional details of the prisoner exchange negotiations between Russia and the United States, saying that they were conducted mainly through the FSB and the CIA.

When asked about other Russians detained abroad, Peskov said “the fate of all our Russians detained abroad in the United States is a matter of constant concern for all our relevant agencies, who will continue the relevant work.”