WASHINGTON -- Canadian-born Paul Whelan and an honorary Canadian citizen were set free Thursday as the United States and Russia completed their largest prisoner swap in post-Soviet history.

"The deal that made this possible was a feat of diplomacy," President Joe Biden said in a news conference after he spoke with some freed prisoners over the phone.

Whelan, Wall Street Journal reporter Evan Gershkovich, and journalist Alsu Kurmasheva were among 16 people freed from Russian detention through the multinational deal.

Russian opposition leader and activist Vladimir Kara-Murza was also freed as part of the deal Thursday.

Kara-Murza was detained in Russia in 2022 after surviving two poisoning attempts. He was granted honorary Canadian citizenship in June 2023. In a release earlier this summer, Prime Minister Justin Trudeau lauded his courage and dedication to democracy.

Trudeau said Thursday that the political prisoners were unjustly detained and their freedom was long overdue.

"These men and women are rejoining their families and loved ones," the prime minister posted on social media. "But the fight for free political expression in Russia is far from over."

Global Affairs Canada said it is committed to putting an end to the use of people as bargaining chips in diplomatic relations, noting that 75 countries have endorsed the Canadian-led Declaration Against Arbitrary Detention launched in 2021.

Foreign Affairs Minister Melanie Joly said in a social media post it is an "immense relief" to see Whelan, Gershkovich and Kara-Murza freed.

"Citizens are not pawns in a geopolitical game. Canada alongside its partners will continue to hold a strong collective front to end this unjust practice," she said.

Whelan was born in Canada to British parents. The family later moved to Michigan. The former U.S. marine and corporate security executive was arrested in 2018 in Moscow, where he was attending a friend's wedding.

Whelan was convicted of espionage charges, which he and the U.S. have said were false, and was serving a 16-year prison sentence.

"Paul was held hostage for 2,043 days," his family said in a statement.

"His case was that of an American in peril, held by the Russian Federation as part of their blighted initiative to use humans as pawns to extract concessions."

Gershkovich was arrested while on a reporting trip in 2023 when Russian authorities claimed, without offering any evidence, that he was gathering secret information for the U.S.

Gershkovich was sentenced to 16 years after a secretive and speedy trial last month. Kurmasheva was also convicted following a two day secret trial the same week as Gershkovich, and many believed at the time it was a sign that a prisoner swap may be in the works.

Biden heralded the prisoner exchange, which took place in Turkey, as a victory, saying it shows the importance of diplomacy.

"This is a powerful example of why it's vital to have friends in this world whom you can trust and depend upon," Biden said.

"Our alliances make Americans safer."

Secretary of State Antony Blinken said American allies, in particular Germany, Poland, Norway, and Slovenia, were critical in making the deal possible.

There have been multiple prisoner swaps negotiated between Russia and the U.S. during the Biden administration but Thursday's involved significant concessions from other countries.

In response to questions, Biden noted that there were difficult conversations with counterparts in Germany in order to make the deal happen.

Germany agreed to release Vadim Krasikov back to Russia. Krasikov was convicted in 2021 of killing a former Chechen rebel in a Berlin park two years earlier, apparently on the orders of Moscow's security services.

Russia also received two alleged sleeper agents who were jailed in Slovenia. Norway returned an academic arrested on suspicions of being a Russian spy, and Poland also sent back a man it detained.

This report by The Canadian Press was first published Aug. 1, 2024.

-- With files from The Associated Press