In a terse statement this morning, Apple said that the white iPhone 4 model will not be available until "later this year" due, again, to still-unspecified manufacturing challenges. The new statement repeats almost word for word a statement issued exactly one month ago, except then Apple said the first white iPhones would be available in the second half of July.

As late as one week ago, at a press conference to address some complaints about the iPhone 4 antenna reception, Apple CEO Steve Jobs reiterated that schedule.

But today's press release is much vaguer about the schedule. The complete statement: "White models of Apple's new iPhone 4 have continued to be more challenging to manufacture than we originally expected, and as a result they will not be available until later this year. The availability of the more popular iPhone 4 black models is not affected."

Online reports emerged earlier this week about the continued delays. These reports put the locus of the manufacturing challenges on Chinese touchscreen glass manufacturer Lens Technology. One issue, according to some reports, is difficulty in working out the correct combination of paint thickness and opacity to satisfy Apple. Another reason is said to be that each machine used to cut the glass covers for the iPhone 4 model can only cut three covers per hour.

The white iPhone was officially revealed at Apple's iPhone 4 unveiling in early June, and is featured in photos on the company's website. But that's the only place you'll find it: the white phone has not been available even for pre-ordering.