He wants to be part of the England squad heading to South Africa next summer - assuming they clinch qualification.
But Hart, overlooked for the games with Slovenia and Croatia, is not looking too far ahead and knows he has strong competition from Maik Taylor and Colin Doyle at St Andrew's despite starting the campaign in the side.
Hart said: "I was obviously struggling for a game at Manchester City. Birmingham have given me the opportunity to play and I was more than happy to join in the summer.
"I know the only way I am going to get the chance to stay involved with the England set-up is if I'm playing regularly in the top division.
"A few people really want those spots with England and a few people are doing really well at the moment.
"I'm dying to be part of it and stay part of it but, at the same time, I can't really look at that too much because I've got Maik (Taylor) snapping at my heels and also Colin (Doyle).
"I've got to concentrate on keeping my place at Birmingham first and foremost and then see what happens from there."
Hart is happy with the defensive form shown by City in conceding only three goals in their opening four league games.
He said: "We have been good defensively from the offset. As a back five, we feel good. We weren't great pre-season but that is pre-season. We have got an understanding of each other."
Aston Villa 11/8, Birmingham 2/1, Draw 9/4