I began interviewing candidates for a position, that was supposed to be created, 2 months ago. I have gone as far as I can go, I have my candidate, but Senior management has not approved the position yet! What is the best way to approach my candidate

I began interviewing candidates for a position, that was supposed to be created, 2 months ago. I have gone as far as I can go, I have my candidate, but Senior management has not approved the position yet! What is the best way to approach my candidate so that they don't go somewhere else?