Josh Lowensohn/CNET

Although Tim Cook has hinted in the past that Apple is looking at other product categories, the company's chief executive on Thursday left no doubt about his plans to look elsewhere.

"There will be new [product] categories," Cook told The Wall Street Journal in an interview published Thursday. "We're not ready to talk about it, but we're working on some really great stuff."

Cook went on to say that any "reasonable" person would expect Apple to be looking to break into other product categories.

There have been near-constant rumblings over the past few years that Apple would be breaking out from computers, music players, tablets, and smartphones, and getting into all-new product categories. Speculation abounds that the company will unveil a new television and could soon launch a wearable device believed to be known as the iWatch.

Despite attempts at prodding, the Journal was unable to get Cook to say exactly what new products his company is working on. He also declined to say when the new product categories might be unveiled.