Apple is working on new iPhones with bigger screens and curved glass including a new sensor able to detect pressure applied on the screen, sources familiar with the matter reported.

The new phones, with screens of 4.7 inches and 5.5 inches, would reportedly be released during the second half of 2014 competing with Samsung's 5.7-inch Galaxy Note 3 released back in September and Samsung's Galaxy Round, which includes a 5.7-inch curved display, announced in early October.

According to Apple's source, who declined to be identified, said the plans and development are not yet complete as Apple spokeswoman, Natalie Kerris, declined to comment about the new phones, Bloomberg informed.

Last week, Apple said it was opening a new plant in Arizona to manufacture components for its devices at the same time it prepaid $578 million to have ready sapphire materials for its smartphones.