A Russian court on Thursday sentenced US basketball star Brittney Griner to nine years in prison after finding her guilty of drug possession and smuggling.
In delivering the verdict, Judge Anna Sotnikova said Griner had committed the crime "deliberately", despite the Olympic gold medallist's claims that it was an "honest mistake".
US President Joe Biden said the sentencing was a reminder that "Russia is wrongfully detaining" the American basketball player.
"It’s unacceptable and I call on Russia to release her immediately so she can be with her wife, loved ones, friends and teammates," Mr Biden said in a statement.
Secretary of State Antony Blinken, who announced last week that the US had proposed a prisoner swap with Russia to bring Griner and fellow US detainee Paul Whelan home, said the decision underscored American concerns about Moscow's use of wrongful detentions.
Elizabeth Rood, the US embassy charge d'affaires and chief hostage negotiator, condemned the ruling as a "miscarriage of justice".
Ms Rood said it did nothing to change the State Department's determination that Griner has been "wrongfully detained". Ms Rood attended every session of Griner's trial.
The Phoenix Mercury, Griner's WNBA team, said it was "heart-broken" and that the verdict serves a "sobering milestone" in the "nightmare" that the basketball star is facing.
Griner has 10 days to appeal, and her lawyers said they expect a hearing at a Moscow court next week. Alexander Boykov, a lawyer for Griner, said the sentence was too harsh and that Russians typically receive a suspended sentence for similar crimes.
"The verdict is absolutely unreasonable, we will certainly file an appeal," Mr Boykov said in a statement.
Griner was detained at a Moscow airport in February and her trial further strained relations between the White House and the Kremlin, with the US proposing a prisoner exchange.
In her final remarks during the trial, Griner said she had not intended to break Russian law by bringing vape cartridges containing cannabis oil into the country.
“I made an honest mistake and I hope in your ruling, it does not end my life,” she said.
Mr Blinken last week spoke to Russian Foreign Minister Sergey Lavrov, urging him to accept a deal that would release Griner and Mr Whelan.
The call was the first between Mr Blinken and Mr Lavrov since before Russia invaded Ukraine on February 24.
Mr Biden said his administration would continue to pursue every avenue possible to secure the release of Griner and Mr Whelan.
US and Russian media outlets have reported that Washington has proposed offering Russian arms dealer Victor Bout in exchange for Griner and Mr Whelan.
Bout is currently serving a 25-year prison sentence in the US for conspiring to kill Americans and providing aid to a terrorist organisation.
Moscow has considered rejecting that deal, Bloomberg reported citing sources close to the Kremlin.
“There has to be a conviction for us to be able formally to conduct the swap,” Fyodor Lukyanov, head of the Council on Foreign and Defence Policy, which advises the Kremlin, said of the Griner trial. “The length of the sentence isn’t a factor in the exchange.”
White House spokeswoman Karine Jean-Pierre on Monday said that Russia made a “bad faith” response to Washington's “substantial offer”.
Griner's lawyers said they were not part of any discussions about a prisoner swap.
The Associated Press contributed to this report