Apple's iPhone 5S is displayed at an Apple shop in Tokyo's Ginza shopping district
Apple's new iPhone 5S is displayed at an Apple shop in Tokyo's Ginza shopping district in this September 20, 2013 file photo. As the smartphone action shifts to the mass market, leaders Samsung Electronics Co Ltd and Apple Inc are under pressure to make their high-end phones more affordable to revive sales. And that may spell trouble for already-softening margins. To match Analysis SAMSUNG-ELEC/SMARTPHONES REUTERS/Yuya Shino/Files REUTERS/Yuya Shino

More signs are surfacing that Apple has definitely set the iPhone 6 release date on mid-September 2014 as new reports from Asia indicate that volume production of the 4.7-inch model is now underway.

Reports from Taiwan and picked up by G4Games suggest that Foxconn and Pegatron have started the assembly of the next iPhone but the production efforts for now is focused on the smaller build, which is tipped as the direct replacement for the 4-inch iPhone 5S.

Putting together the phablet-size 5.5-inch iPhone 6 is expected to follow but not until the 4.7-inch edition is ready for rollout, the report added. Going by the hints offered by Apple so far - that its pipeline of fresh products will begin to come out fall of 2014 - September is likely the month that the device will hit store shelves worldwide.

And if G4Games' source is to be believed, Apple will again fire up its various production lines in China by the end of September to build the bigger iPhone 6 together with two more of the tech giant's flagship iOS devices.

"Both the next iPad Mini and iPad Air (2) will also enter mass production in September," G4Games reported.

While the 4.7-inch iPhone 6 is given a target date for commercial availability, it remains unclear when the phone's jumbo-size sibling will touch down or if it would be simultaneously pushed out with the 2014 iPad refreshes.

A recent note, however, from Ming-chi Kuo of KGI Securities could offer clues. The well-known Apple insider predicted that the first iOS phablet will make its debut a later time than the smaller version - likely by December 2014 or as late as January 2015.

Kuo pointed to complicated production challenges as the cause of the delay, which a DigiTimes report this week has disputed.

The Taiwanese publication claimed that Apple has little or no problem at all when it comes to the 5.5-inch iPhone 6 production. Still, the device will not launch alongside the smaller iPhone and this is a deliberate strategy on Apple's part, DigiTimes said.

The purpose is to avoid competition between the two 2014 iPhones, the report explained.

Meanwhile, Katy Huberty of Morgan Stanley added her voice to the growing anticipation that a new iPhone is coming very soon, MacRumors said in a report.

The iPhone 6 release date is likely between September 19 and 26 this 2014, which seemingly is supported by Apple's spending increase that Huberty connects to fresh products geared for launch in the remaining months of the year, specifically that of the next iPhone and the iWatch.