Apple Inc. Chief Executive Steve Jobs said on Thursday he is not too worried that its new iPhone mobile telephone will dampen sales of the popular iPod music and video players.

We can report to you that it hasn't so far, Jobs told the Wall Street Journal in an interview, when asked if the iPhone, which also plays music and video, would cannibalize Apple's iPod business.

I'm not too worried about that, Jobs said.

The iPhone goes on sale in the United States on Friday evening and will cost $500 or $600, depending on memory capacity. It will require a two-year service contract with AT&T Inc.

Jobs also said Apple's forecast for iPhone demand could be too low.

We're building a fair number of them, but we may not (meet demand), Jobs said, without revealing how many units the company will have on hand at launch. We've taken our best guess, but it wouldn't surprise me at all if it ain't enough.

Shares in Apple fell 1.1 percent to $120.56 on Thursday on Nasdaq. The stock has risen 30 percent since Jobs unveiled the iPhone in January.