Brittney Griner plead guilty on Thursday to carrying cannabis oil into Russia in her luggage in February.
Griner, 31, plead guilty during day 2 of her trial in Khimki, outside Moscow on Thursday, July 7.
"I'd like to plead guilty, your honor. But there was no intent. I didn't want to break the law," Griner said, according to Reuters.
She said she packed her luggage quickly and didn't realize the drugs were in her bag.
"I'd like to give my testimony later. I need time to prepare," she added. Her statement was translated into Russian for the court.
Griner's trial is expected to last several weeks or months, according to reports.
The two-time Olympic gold medalist and WNBA champion wore a red t-shirt with the word "Crenshaw" on the front and red jogging pants to court.
She was detained at Moscow airport in February on charges of carrying vape cartridges containing cannabis oil in her luggage. If convicted, the charge could carry a 10-year prison sentence.
Griner wrote a letter to the Biden administration pleading for help. The letter was delivered to the US President on Monday, July 4.
Joe Biden spoke to Griner's significant other, Cherelle Griner, on the phone, and assured her that he is working to win her release as soon as possible.
Fans and players in the WNBA and NBA show support for the political prisoner at every game.
Her initials "BG" are painted on WNBA and NBA home courts, and players, such as Phoenix Mercury teammate Diana Taurasi and Celtics star Jaylen Brown, wear t-shirts with her name and initials printed on them.