Ahead of the release of the NPD Group’s monthly report for June tomorrow, Microsoft has announced that sales of the Xbox One in the United States “more than double[d]” in June after the $400 model went on sale on June 9.

Microsoft failed to provide us with any specific sales figures for the month, nor did it update us on the total number of Xbox One consoles it has sold. Instead, all it provided us with is the vague statement about selling more than twice as many consoles in the U.S. “since June 9″ as compared with May. The language in this announcement is confusing, and we’ve followed up with Microsoft to find out exactly what period it accounts for.

Regardless, as we never got sales numbers for May, either, it makes it difficult to glean much from this. The one thing we can tell is that the company did see a sales bump following its E3 announcements and the system being offered for $400 without Kinect.

Microsoft announced in May that it would sell the Xbox One without Kinect for the first time beginning in June. This brought the system’s price down $100 from that of the $500 Kinect bundle, which continues to be sold alongside the Kinect-less version. The company has insisted it will continue to support Kinect, and has claimed that dropping it will ultimately lead to more Kinect sales overall.

To date, Sony’s PlayStation 4 has outsold the Xbox One worldwide. The latest official numbers put the PS4 at 7 million units sold (as of April 6) and the Xbox One at 3 million units sold (as of December 31), with 5 million shipped to retailers (as of March 31).

Did offering an Xbox One without Kinect get you to pick one up in June? Let us know in the comments.