The newest iPad Mini with Wi-Fi and cellular capability (3G/4G) has yet to reach carrier stores in the US, pointing to Apple's tight control of supply.

Verizon shows the iPad Mini with Retina Display back ordered until December 16, as of Friday morning Pacific time, while AT&T is still showing 21-28 days when the device is ordered online.

Neither carrier, when contacted by CNET, could provide information about when the iPad MiniRetina would reach its stores.

T-Mobile's Web page for the iPad Mini Retina is showing, as of Friday, that the tablet will be "available for shipment soon," but no target date is given.

Meanwhile, the availability of all iPad Mini Retina models -- both Wi-Fi-only and cellular versions -- on Apple's store page has improved somewhat: availability is now 5-7 days, a slight improvement over the 5-10 days that the company had been showing last week.

Cellular models of the iPad Mini Retina are also available for walk-in purchase at many Apple stores across the US, despite the fact that this is not possible at Verizon and AT&T.