The U.S. government has offered a deal to Russia for the release of Brittney Griner and Paul Whelan, another American jailed in the country, ESPN reports. This is the first time the Biden administration has shared a public plan regarding its efforts to bring Griner home.

The U.S. has offered Viktor Bout, a Russian arms dealer known as the “Merchant of Death,” in exchange for Griner, CNN reports. Bout was sentenced to 25 years in prison after allegedly planning to sell millions of dollars in weapons illegally.

Despite the offer, officials have refrained from releasing additional details on the “substantial offer.”