Apple is currently working hard on improving its next flagship smartphone, which includes cutting down the thickness of the iPhone 6.

A recent report from South Korean site ET NEWS has claimed that the Cupertino-based tech giant's upcoming iPhone will be incredibly thin, reportedly measure only 6 millimeters thick (or "depth").

In comparison, the 4-month old iPhone 5S is currently has a depth of 7.6 millimeters, which is still thinner than many of other high-end smartphones out there. The old-school iPhone 3GS is over 12 millimeters thick, which is twice as thick as the latest model.

According to sources somewhere in the Chinese IT and supply chain universe, the next iPhone is also dubbed as "iPhone Air," although it is a bit too early to start speculating on names right now.

Apple's next smartphone device will not only be thin, but also is likely to be larger in display size, reportedly approaching the 5-inch phone tablet. The reason the iPhone 6 could be so thin is because it is also said to have a larger screen that would allow some more space for internal components.

The iPhone 6 production will be split between two models -- 4.7- and 5.7-inch variants -- and the 5.7-inch model could even end up being bigger than 5.7-inches. Both models are rumored to come with at least "one form of biometrics, which could include fingerprint or eye recognition."

Similarly, analyst Ming-Chi Kuo, who has an impressive track record of predicting Apple gadgets ahead of time, says the new super-thin smartphone will feature a nearly 5-inch screen.