Apple Inc. said Monday its online stores in the U.S. and U.K. are sold out of the iPhone, a sign supplies are being winnowed ahead of the launch of the device’s next generation featuring faster Internet surfing speeds.

The Cupertino-based company confirmed that the iPhone is out of stock online, but added that brick-and-mortar stores run by Apple and iPhone carriers including AT&T Inc. might still have units available. Apple has been known for clearing out its inventory of a certain product ahead of a major upgrade.