Apple event 9 September iPhone 6s
Apple has invited the world's media to an event in San Francisco on 9 SeptemberScreenshot

As expected, Apple has invited the world's press to an announcement in San Francisco on 9 September. The iPhone 6s and iPhone 6s Plus are both widely expected to be revealed at the event.

Kicking off at 10am PST (6pm BST), the event will take place at the Bill Graham Civic Auditorium. A live video stream is likely to be broadcast on Apple's website, as it was when the iPhone 6 and Apple Watch were announced this time last year.

The invitation, emailed to press today (27 September) shows the top half of the Apple logo with a background of multiple colours and the message "Hey Siri, give us a hint" in reference to the iPhone's voice-activated personal assistant, Siri. A hint might not be needed though, as the iPhone 6s and 6s Plus have leaked widely in the run up to their big debut.

Both handsets are expected to look almost identical to the current iPhone lineup, but a major change will be to their screens. Force Touch, already used on the Apple Watch and newest MacBooks, will come to the new iPhones. This measures how hard a user presses on the screen and can be used as an entirely new gesture command. The feature could also add a new element to gaming.

A new version of the Apple TV is likely to be unveiled at the same event, featuring a new touch screen remote control, a new iOS-based operating system, and its own application store.

The event will also see Apple show off the final build of iOS 9, which will be made available for the iPhone and iPad ranges soon in the coming weeks, and El Capitan, the latest instalment of Apple's Mac OS X software which will also go on general release this autumn. Finally, Watch OS 2 will also be covered by the 9 September event, bringing a range of new software features to the Apple Watch.