NPD Group research retail has revealed the exact number of units sold in the United States territory for Xbox One and Playstation 4. According to Windows Central, both systems shared a total of ~3.1 million consoles sold with PS4 selling 1,568,000 & Xbox One / Xbox One S selling 1,511,000.
No total hard sales have been specified by Microsoft,  although they did release a statement to WindowsCentral confirming that “Xbox had seen year-over-year growth, with record-breaking Xbox Live engagement for November and December”.  Here’s what they had to say:

December was the biggest month ever for Xbox One sales in the U.S. and Xbox One was the only eighth generation console with year-over-year growth, according to NPD. In addition, Xbox One was the top-selling console over the second half of 2016, following the announcement of Xbox One S at E3.
In November and December we saw Xbox Live engagement reach an all-time high of 3.9 billion hours, up 23 percent compared to 2015 driven by fan excitement for the greatest games lineup. Looking ahead, we expect 2017 to be a special year for gamers thanks to the upcoming launch of the most powerful console ever in Project Scorpio and a terrific portfolio of new games with Xbox Live support on Xbox One, Windows 10 or both. – Mike Nichols, Corporate Vice President, Xbox Marketing, Microsoft

In a similar news, an upgraded Xbox One is slated to arrive Holiday 2017, an akin project of PS4 Pro with enhanced graphics, better performance, and VR support. No unambiguous details have been given about Project Scorpio aside from true 4k support. Microsoft is unsure if they will disclose anything at all about Scorpio before E3 but our guess is a little event devoted to Project Scorpio before the big happening in June.
For more about Xbox, PS4 and Project Scorpio, stick with us!