(CNN) — WNBA star Brittney Griner has been released from Russian detention, President Joe Biden said Thursday.

A source familiar with the matter tells CNN that the swap involves convicted Russian arms dealer Viktor Bout. The swap did not include another American that the State Department has declared wrongfully detained, Paul Whelan.

“She’s safe, she’s on a plane, she’s on her way home,” Biden said at the White House Thursday morning alongside Griner’s wife, Cherelle. “After months of being unjustly detained in Russia, held under untolerable circumstances, Brittney will soon be back in the arms of her loved ones, and she should have been there all along.”

Biden acknowledged that Griner’s release was occurring while Whelan remained imprisoned, saying that Whelan’s family “have to have such mixed emotions today.”

“This was not a choice of which American to bring home,” Biden said. “Sadly, for totally illegitimate reasons, Russia is treating Paul’s case differently than Brittney’s. And while we have not yet succeeded in securing Paul’s release, we are not giving up. We will never give up.”

Biden said efforts to bring Griner home took “painstaking and intense negotiations” as he thanked members of his administration who were involved.

“This is a day we’ve worked toward for a long time. We never stopped pushing for her release,” he said.

Asked when Griner would be home following his remarks, Biden indicated it would be in the next “24 hours.” As for what he would say to Whelan’s family, he said, “We’re speaking to them.”

Cherelle Griner thanked the administration for helping secure her wife’s release and said she was “overwhelmed with emotions.”

Both she and Brittney Griner “will remain committed to the work of getting every American home, including Paul, whose family is in our hearts today,” she added.

Brittney Griner — who, for years, had played in the off-season for a Russian women’s basketball team — had been detained since February, when she was arrested on drug smuggling charges at an airport in the Moscow region. Despite her testimony that she had inadvertently packed the cannabis oil that was found in her luggage, she was sentenced to nine years in prison in early August and was moved to a penal colony in the Mordovia republic in mid-November after losing her appeal.

‘The only deal we could make right now’

Biden gave final approval for the prisoner swap freeing Griner over the past week, an official familiar with the matter said, adding that Biden was updated on the swap as it was taking place Thursday morning.

He was briefed throughout the morning as he awaited confirmation that Griner was back in US hands, a US official says. Once that happened, Biden spoke with Griner from the Oval Office, with Cherelle Griner, Vice President Kamala Harris and Secretary of State Antony Blinken was also on the call, a second official said.

Biden was “personally involved and in constant touch” with his team as this deal came together in the final days and after he gave his personal green light to execute the trade. The briefings — and questions Biden asked his team — were constant, a senior administration official says.

The official added that this was the right deal to make, but notably said this was “the only deal we could make right now.”

The Russians signaled recently that they were only willing to negotiate for Griner and not Whelan, a US official said. That is because Russia has been handling their cases differently based on what each has been accused of.

The Biden administration repeatedly made offers to get Whelan released as part of this deal, even after Russia made clear only Griner was acceptable.

In the end, when it was clear Russia was going to refuse on Whelan, the US had to accept it.

“It was a choice to get Brittney or nothing,” the US official said.

The official says that was a “difficult decision” for Biden, but again, one he felt he had to make.

Whelan family ‘devastated’

Whelan, a US, Irish, British and Canadian citizen, was detained at a Moscow hotel in December 2018 by Russian authorities who alleged he was involved in an intelligence operation. He was sentenced to 16 years in prison on espionage charges he has vehemently denied. Whelan had been carrying out his sentence at a different labor camp in Mordovia, an eight-hour drive from Moscow, where he told CNN in June 2021 he spent his days working in a clothing factory that he called a “sweatshop.”

Whelan’s family expressed happiness at the news that Griner is on her way home but said Thursday they are “devastated” that he was left behind.

“It’s a great day for the families of the wrongfully detained and we feel wonderful for them,” David Whelan, Paul’s brother, said on “CNN This Morning.” “But we do worry about what’s in Paul’s future. I think it’s become clear that the US doesn’t have any concessions that the Russian government wants for Paul. So I’m not really sure what the future holds.”

The Biden administration told Whelan’s family ahead of the Griner announcement, David Whelan said.

In an email to the media, David Whelan said his family was “devastated” at the news and increasingly worries that Paul won’t survive the rest of his sentence.

“I can’t even fathom how Paul will feel when he learns. Paul has worked so hard to survive nearly four years of this injustice. His hopes had soared with the knowledge that the US government was taking concrete steps for once towards his release. He’d been worrying about where he’d live when he got back to the US,” David Whelan said in his statement.

“And now what? How do you continue to survive, day after day, when you know that your government has failed twice to free you from a foreign prison? I can’t imagine he retains any hope that a government will negotiate his freedom at this point. It’s clear that the US government has no concessions that the Russian government will take for Paul Whelan. And so Paul will remain a prisoner until that changes,” Whelan said.

‘Merchant of Death’ included in swap

Bout has returned home to Russia, the Russian foreign ministry. The prisoner exchange with Griner was “completed successfully at Abu Dhabi Airport” on Thursday, state media added.

Bout, nicknamed the “Merchant of Death,” is a former Soviet military officer serving a 25-year prison sentence in the United States on charges of conspiring to kill Americans, acquire and export anti-aircraft missiles, and provide material support to a terrorist organization. Moscow had slammed his sentencing in 2012 as “baseless and biased” and Bout has maintained he is innocent.

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