Russia freed WNBA star Brittney Griner early today in a dramatic prisoner exchange, as the US released notorious Russian arms dealer Viktor Bout but failed to win freedom for another American, Paul Whelan, who has been jailed for nearly four years.

The swap, at a time of heightened tensions over Ukraine, achieved a top goal for President Joe Biden but carried a heavy price.

“She’s safe, she’s on a plane, she’s on her way home,” Biden said from the White House, where he was accompanied by Griner’s wife, Cherelle, and administration officials.

The deal, the second such exchange in eight months with Russia, procured the release of the most prominent American detained abroad. Griner is a two-time Olympic gold medalist whose months-long imprisonment on drug charges brought unprecedented attention to the population of wrongful detainees.

Biden’s authorisation to release a Russian felon once nicknamed “the Merchant of Death” underscored the escalating pressure that his administration faced to get Griner home, particularly after the recent resolution of her criminal case and her subsequent transfer to a penal colony.

The Russian Foreign Ministry also confirmed the swap, saying in a statement carried by Russian news agencies the exchange took place in Abu Dhabi and that Bout had been flown home.

Russian and US officials had conveyed cautious optimism in recent weeks after months of strained negotiations, with Biden saying in November he was hopeful that Russia would engage in a deal now the midterm elections were completed. A top Russian official said last week a deal was possible before year’s end.

Even so, the fact the deal was a one-for-one swap was a surprise given US officials had for months expressed their determination to bring home both Griner and Paul Whelan, a Michigan corporate security executive jailed in Russia since December 2018 on espionage charges that his family and the US government has said are baseless.

“We’ve not forgotten about Paul Whelan,” Biden said. “We will keep negotiating in good faith for Paul’s release.”

Whelan’s brother David said in a statement he was “so glad” for Griner’s release but also disappointed for his family. He credited the White House with giving the Whelan family advance notice and said he did not fault officials for making the deal.

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“The Biden Administration made the right decision to bring Ms Griner home, and to make the deal that was possible, rather than waiting for one that wasn’t going to happen,” he said.

In releasing Bout, the US freed a former Soviet Army lieutenant colonel whom the Justice Department once described as one of the world’s most prolific arms dealers. Bout, whose exploits inspired a Hollywood movie, was serving a 25-year sentence on charges that he conspired to sell tens of millions of dollars in weapons that US officials said were to be used against Americans.

The Biden administration was ultimately willing to exchange Bout if it meant Griner’s freedom. The detention of one of the greatest players in WNBA history contributed to a swirl of unprecedented public attention for an individual detainee case — not to mention intense pressure on the White House.

Griner’s arrest in February made her the most high-profile American jailed abroad. Her status as an openly gay black woman, locked up in a country where authorities have been hostile to the LBGTQ community, infused racial, gender and social dynamics into her legal saga and made each development a matter of international importance.

Her case not only brought unprecedented publicity to the dozens of Americans wrongfully detained by foreign governments, but it also emerged as a major inflection point in US-Russia diplomacy at a time of deteriorating relations prompted by Moscow’s war against Ukraine.

The exchange was carried out despite deteriorating relations between the powers. But the imprisonment of Americans produced a rare diplomatic opening, yielding the highest-level known contact between Washington and Moscow — a phone call between Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov — in more than five months.

In an extraordinary move during otherwise secret negotiations, Blinken revealed publicly in July that the US had made a “substantial proposal” to Russia for Griner and Whelan. Though he did not specify the terms, people familiar with it said the US had offered Bout.

Such a public overture drew a chiding rebuke from the Russians, who said they preferred to resolve such cases in private, and carried the risk of weakening the US government’s negotiating hand for this and future deals by making the administration appear too desperate. But the announcement was also meant to communicate to the public that Biden was doing what he could and to ensure pressure on the Russians.

Cherelle Griner, Brittney Griner's wife, speaks in the Roosevelt Room of the White House in Washington on Thursday about the prisoner swap, with President Joe Biden and Vice President Kamala Harris. Photo / AP

Besides the efforts of US officials, the release also followed months of back-channel negotiations involving Bill Richardson, the former US ambassador to the United Nations and a frequent emissary in hostage talks, and his top deputy, Mickey Bergman.

Griner was arrested at the Moscow’s Sheremetyevo Airport in February when customs officials said they found vape canisters with cannabis oil in her luggage. She pleaded guilty in July, though still faced trial because admitting guilt in Russia’s judicial system does not automatically end a case.

She acknowledged in court that she possessed the canisters, but said she had no criminal intent and said their presence in her luggage was due to hasty packing.

Before being sentenced on August 4 and receiving a punishment her lawyers said was out of line for the offence, an emotional Griner apologised “for my mistake that I made and the embarrassment that I brought on them.” She added: “I hope in your ruling it does not end my life.”

Her supporters had largely stayed quiet for weeks after her arrest, but that approach changed in May once the State Department designated her as unlawfully detained. A separate trade, Marine veteran Trevor Reed for Konstantin Yaroshenko, a Russian pilot convicted in the US in a cocaine trafficking conspiracy, spurred hope that additional such exchanges could be in the works.

Whelan has been held in Russia since December 2018. The US government also classified him as wrongfully detained. He was sentenced in 2020 to 16 years in prison.

Whelan was not included in the Reed prisoner swap, escalating pressure on the Biden administration to ensure that any deal that brought home Griner also included him.

- Eric Tucker, Matthew Lee and Zeke Miller, AP