Detained American Whelan: I'm disappointed more has not been done for my release

Paul Whelan, a former U.S. Marine who is serving 16 years in Russia on charges of espionage which he denies, told CNN he was disappointed that more had not been done to secure his release following a prisoner swap that will see basketball star Brittney Griner return home.

"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.