Sony officially announced the existence of the Xperia Z4 flagship device last month, although it only received confirmation on a Japanese release. There are rumors that Sony could launch this device in the west under a different name but they haven't yet confirmed any such details suggesting the Xperia Z4 will launch in the U.S. Sony Mobile is apparently getting ready for a launch of the device outside of its native Japan however, as Sony Xperia China has seemingly confirmed the launch event for the device on their Weibo account earlier this morning. This means that China could be the first region outside of Japan to get the Sony Xperia Z4, and it also points to the possibility that we'll see the device come stateside.
Sony's teaser image on Weibo displays that they have an event scheduled for May 26th which is just next week, and in the teaser it displays a portion of the Sony Xperia Z4. This isn't direct confirmation from the mouth of Sony Mobile China, but it's pretty straightforward nonetheless. China may not be the only country to receive the phone as Taiwan, Hong Kong, and India are also potentially expected launch regions, but whether or not it makes it to those countries is still unclear.
Sony typically hasn't had the strongest presence in the U.S. with their smartphones, let alone their flagships, and while it is likely the U.S. could see a version of the Xperia Z4 at some point, it's entirely possible that it could be a while after it releases in other locations. Speculations suggest that if Sony launches the Xperia X4 here in the states it may come along under the name Xperia Z3+ as it's more of an enhanced version of their current Xperia Z3 flagship than a completely new device, but even if that is the case the improvements are not only needed to keep up with the other flagships from other OEMs, but would likely be much appreciated by consumers looking for a more powerful experience from the premium Sony Xperia line. So far there hasn't been any pricing details released about the Xperia Z4 for the Chinese market, but Sony is more than likely going to share that information at next week's event.