Sen. John McCain has been hospitalized at Walter Reed Medical Center outside Washington D.C. for side effects from his cancer treatment, his office said in a Wednesday release.

"Senator McCain is currently receiving treatment at Walter Reed Medical Center for normal side effects of his ongoing cancer therapy," the release said. "As ever, he remains grateful to his physicians for their excellent care, and his friends and supporters for their encouragement and good wishes. Senator McCain looks forward to returning to work as soon as possible."

McCain has been receiving treatment since being diagnosed with a glioblastoma -- a cancerous brain tumor -- last July.