The year 2013 is reserved for the iPhone 5S but Apple fans will have to wait a little longer for the iPhone 6, which at the moment is fixed for a June 2014 release date, a new report said.

While Apple is feeling the mounting pressure from phablet-size smartphones like the Samsung Galaxy S4 and the HTC One, it is doubtful that the tech giant will be able to produce its own version of the oversized mobile phones anytime soon, Jeffries managing director Peter Misek told Bloomberg TV in an interview.

He added that consumers' interest on large-screen smartphones are definitely growing but looking at Apple's current capabilities, "we don't think they can produce a larger screen iPhone until the middle of next year."

Apple is more likely to offer the 4-inch iPhone 5S this year and wait out until next year before it releases the 4.8-inch iPhone 6, Mr Misek said, indirectly alluding to the recent statement of Apple CEO Tim Cook, in which he hinted that the company will not issue products that fraught with technology trade offs.

The iPhone 5S, Mr Misek said, should begin production between late June and early July and its release date pegged for the initial weeks of September, which is the latest release date on Apple's calendar.

He added that pitting the 5S against the Galaxy S4 will lead to a mismatch because "S4 is a 5-inch screen product ... and the iPhone 5S is a 4-inch screen product."

It would be hard for the Apple flagship to compete against the new Samsung handset, Mr Misek explained, adding that at the moment more and more consumers are planning to buy large-screen smartphones, which is a developing trend that is especially true outside of the U.S. market.

It appears too that Apple will rely heavily on underneath upgrades for the iPhone 5S to continue attracting consumers worldwide. The 5S is expected to sport faster processor, killer camera features and better security via the fingerprint sensor embedded on its Home button.

Apple is also rumoured to release the iPhone 5S in numerous colour variants apart from the regular black and white, which is a move seen to offset disappointments for the incremental upgrades that it will deliver.