Montgomery said: "I'm in talks about my contract, but these things take time and I'm not wanting to rush things. I'm fully focused on playing in two important matches over the Christmas period.
"I'll leave negotiations to other people, but hopefully in the next couple of weeks there might be something sorted out.
"I've been with this club through thick and thin and can honestly say I love the Blades. When I started we used to get 11,000 at home games, now we regularly get in excess of 25,000 week after week, so Sheffield United is a massive club."
Montgomery added: "I'm happy to be a part of what is happening at Sheffield United and I'm in no rush to leave it behind."