How can I direct attention on an breath without consciously breathing?

In every guided meditation or in the books I've read on meditation, I've been told to observe and hold sustained awareness towards the the 'meditation object', that is my breathing. When I do that, though, I stop breathing automatically and instead have to control my breaths. Can someone explain to me what's going on? Is this okay? Or is there a way I can observe my breath whilst automatically breathing?