Washington, Aug 2 (IANS): Three American citizens, Paul Whelan, Evan Gershkovich, Alsu Kurmasheva and American green card holder Vladimir Kara-Murza, have returned to the United States after a prisoner swap with Russia on Thursday that US National Security Advisor Jake Sullivan described as "one of the largest and certainly the most complex exchange in history".

US President Joe Biden and Vice President Kamala Harris, along with the families of the freed individuals, welcomed them as they arrived at the Joint Base Andrews from Ankara in Turkey.

Announcing their arrival Biden stated on X, "Tonight is about reuniting families. Welcome home, Paul, Evan, and Alsu. You're right where you belong".

Earlier, Biden invited the family members to his Oval Office the moment the exchange was completed on the tarmac in Ankara.

"Today, I stood beside the families of Paul, Evan, Alsu, and Vladimir in the Oval Office as they spoke to their loved ones for the first time since they regained freedom. These families never lost hope," he said.

At least two dozen detainees were involved in the swap with prisoners released from seven countries -- the US, Norway, Germany, Poland, Russia, Belarus and Slovenia.

Gershkovich, the 32-year-old correspondent for The Wall Street Journal, was arrested by Russian authorities in March 2023 on the charges of espionage. He was convicted last month and sentenced to 16 years in a high-security prison.

Whelan, the 54-year-old ex-Marine, was arrested in Russia in December 2018 on espionage charges and was serving a 16-year jail term.

Vladimir Kara-Murza, a British-Russian dissident and Pulitzer Prize-winning columnist, who was sentenced to 25 years in prison on treason-related charges was also released from prison.