Detained American Paul Whelan told CNN he is “disappointed” the Biden administration has not done more to secure his release, meaning he’s been left behind in Russia after fellow detained American Brittney Griner was freed on Thursday.

“I am greatly disappointed that more has not been done to secure my release, especially as the four year anniversary of my arrest is coming up. I was arrested for a crime that never occurred,” he said in an exclusive phone call from the penal colony where is being held in a remote part of Russia. “I don’t understand why I’m still sitting here.”

Whelan said he was happy that Griner was released but told CNN he “was led to believe that things were moving in the right direction, and that the governments were negotiating and that something would happen fairly soon.”

When asked if he was surprised not to have been included in the swap for Russian arms dealer Viktor Bout, he told CNN he was.