A video uploaded to YouTube by a striking Verizon worker shows Verizon CEO Lowell McAdam addressing workers at a picket line in DeWitt, New York.

McAdam made an unannounced stop in DeWitt, where he spoke with the workers for 15 minutes before attending a meeting with managers at the Verizon office. McAdam told the striking workers he didn't understand why employees had walked off the job Wednesday, in the largest U.S. work stoppage since 2011.

"I don't know what you're being told about why the union leadership didn't accept mediation," McAdam said. "For me, if there's a disagreement and after 10 months you can't get there, mediation makes a lot of sense."

When workers questioned the CEO about Verizon transferring jobs overseas, McAdam claimed he wasn't aware of such changes. "At 178,000 employees, you think there might be things going on around the business I don't know about?" he said. He told them he would look into the claims of outsourcing.

McAdam made headlines last week when he referred to Bernie Sanders' economic views as "uninformed" and "contemptible." McAdam posted the comments shortly after Sanders visited a group of striking workers to pledge solidarity and call out McAdam for his labor policies.

Watch the video of McAdam's comments at the picket line below: