(NewsNation) — Steve Zissou, the attorney for Russian arms dealer Viktor Bout, says we’re “very close” to an exchange deal for WNBA star Brittney Griner and former Marine Paul Whelan.

Prosecutors are calling on a state narcotics expert, who analyzed the cannabis found in Griner’s luggage at an airport in Moscow. Griner’s lawyers are calling the report flawed.

Last month, Griner pleaded guilty to her charges, stressing that she did not intend to break the law and that she wasn’t aware of the illegal substance when she packed her suitcase in a hurry.

If convicted, the two-time Olympic gold medalist could face 10 years in prison.

Bout, also referred to as the “merchant of death,” is currently serving a 25-year prison sentence in the United States after he was convicted in 2011 of conspiracy to kill Americans and aiding a terrorist organization.

“Hopefully, we’ll be able to reach an agreement in a relatively short time, so long as the chatter sort of slows down. I think it has been helpful,” Zissou said during an appearance Tuesday night on “NewsNation Prime.” “I don’t think it was helpful for for the American Secretary of State to announce that there was an offer made. I think that might have delayed things, but we’ll see.”

Russia has been trying to get Bout back for decades.

“In Russia, he’s a respected citizen. You call Paul Whelan a hostage … But in Russia, he’s a notorious spy, right? So you really have to understand this, and to figure things out, you’ve got to look at it from both perspectives,” Zissou added.