The chairman of the Senate Armed Services Committee said on Tuesday that he will block the administration from dividing leadership of the National Security Administration and U.S. Cyber Command between two people.

Right now, one person serves as the head of both the NSA and Cyber Command. Sen. John McCain, R-Ariz., said he is “troubled” by reports that President Obama is trying to separate that into two roles and will do what he can to prevent the change.