Brittney Griner personally reached out to President Joe Biden, urging him to help get her out of Russian custody, according to her representatives.
A handwritten letter from Griner, portions of which were made public, was delivered to the White House on Monday. In it, she expressed fears she will be held in Russia "forever."
"As I sit here in a Russian prison, alone with my thoughts and without the protection of my wife, family, friends, Olympic jersey, or any accomplishments, I'm terrified I might be here forever," Griner wrote to the president.
On Feb. 17, the WNBA star was detained at Russia's Sheremetyevo International Airport after being accused of having vape cartridges containing hashish oil, which is illegal in the country.
"It hurts thinking about how I usually celebrate [the Fourth of July] because freedom means something completely different to me this year," she wrote.
Last Friday marked the first day of Griner's trial. She appeared in person at a courtroom in Khimki, a suburb of Moscow, ABC News reported. Her detention in Russia was extended to Dec. 20, the expected length of her trial.
Griner's family and friends have called for the Phoenix Mercury star to be released and for the Biden administration to act.
"I just keep hearing that, you know, he has the power. She's a political pawn," Griner's wife, Cherelle Griner, told ABC News' Robin Roberts in May. "So, if they're holding her because they want you to do something, then I want you to do it."
In the Monday letter, the basketball star asked Biden to not forget about her and other American detainees in the country and to work toward bringing them back to the U.S.
"I still have so much good to do with my freedom that you can help restore. I miss my wife! I miss my family! I miss my teammates! It kills me to know they are suffering so much right now. I am grateful for whatever you can do at this moment to get me home," she said.
It's unknown if Biden read the letter, but National Security Council Spokesperson Adrienne Watson said in a statement obtained by ABC News the president "has been clear" about seeing all detainees who are wrongfully detained oversees, including the WNBA star, released.
"The U.S. government continues to work aggressively – using every available means – to bring her home," Watson said.
ABC News' Courtney Condron and Sarah Kolinovsky contributed to this report.