WNBA star Brittney Griner made a direct plea to President Joe Biden to stand up for her in an emotional letter sent to the White House on Monday as she remains detained in Russia on drug charges.

Griner, who was held at a Moscow airport on Feb. 17 when a search of her luggage allegedly revealed multiple cannabis oil vape cartridges, went on trial on Friday and could face up to 10 years in a Russian jail.

The case takes place against a backdrop of high tension between Moscow and Washington over the conflict in Ukraine. U.S. officials say Griner has been detained wrongfully.