Marred by production delays, Apple's new smartphones, the iPhone 5s and iPhone 6, are perceived to face further delays and pushed towards an August or September and a 2014 release, analyst Glen Yeung said.

Citbank analyst, Mr. Yeung, believes that Apple will be pushing back its release of the iPhone 5S, to August or September, while the iPhone 6 will be seen by next year as a way keeping up to Apple founder Steve Jobs strict quality standards that has been a trademark of Apple brands.

Yeung's note released Sunday also said that Apple plans to roll out a version of its lightweight MacBook Air notebook computer with a Retina display.

CNET stated that the probable reason for the delay is "production issues". Yeung is not the first analyst to say that Apple will delay the release date of its much awaited smartphones.

According to Jefferies analyst Peter Misek, the rumoured low cost iPhone 5S will most likely be delayed. Misek also said that the possible cheaper iPhone launch could be pushed to this year's fourth quarter and an iPhone 6 probably would not come out until June 2014.

"iPhone 5S is having preproduction issues with mass production at least a month or more away. This combined with the publicly discussed delay of iOS 7 puts a July availability at risk. We continue to believe there is almost no chance the iPhone 6 launches in CY13 [calendar year 2013] due to supply chain issues," Misek said.

Another analyst predicted a possible delay on iPhones' release date this year. According to a report by KGI Securities analysts Ming-Chi Kuo, people should expect to see the aforementioned device later this year.

Kuo said that part of the problem with the iPhone 5S products lies in the rumored fingerprint sensor that Apple is adding. Finding the right color coatings to prevent interference with the sensor has been an unforeseen challenge.

The Jeffries analyst provided a similar claim in an estimate he provided in February of this year. These reports do seem to contradict many of the rumors circulating about the iPhone 6's release date.

Some of the rumoured features of the next iPhone are Retina or IGZO screen display, A7 quad core chip processor, iOS 7, 128GB internal storage, 13 mega-pixel camera, and longer battery life. The lack of NFC support on the iPhone 5 was one of the biggest criticisms aimed at Apple's smartphone.

The low cost iPhone 5S, on the other hand, is rumoured to sport a plastic casing, 4-inch screen display, dual core processor and 8-megapixel camera.

As usual, Apple did not comment on the rumours about iPhone 6 or iPhone 5S.