Apple defends Xbox streaming block on iPhones
Microsoft has confirmed that its new game streaming service, xCloud, will not appear on Apple devices.
The Netflix-like game service will launch in September for Android devices, offering a library of more than 100 games for a monthly fee.
Apple said its app store rules require that each game is submitted individually for review.
Microsoft said Apple was the only major platform to "deny consumers from cloud gaming and game subscription services".
Another major game streaming service, Google's Stadia, has had similar problems - it too is available on Android and not Apple's iOS.
Microsoft is poised to roll its streaming feature into the top tier of its Game Pass product, which will cost £10.99 a month in the UK.
Some had hoped that Microsoft's service would be coming to the Apple App Store, because it has operated a test version for several months - although with only one single game available.
Apple, however, dismissed those hopes in a statement issued to Business Insider.
"Gaming services can absolutely launch on the App Store, as long as they follow the same set of guidelines applicable to all developers," the statement read.
That includes "submitting games individually for review, and appearing in charts and search".
However, that is not how Microsoft or Google's game streaming subscription apps work. The idea is that one app acts as a browser for all the available games, which can be streamed instantly from the menu.
Microsoft also promises that new games will be added "all the time" and first-party titles will be available to stream on the same day as their general release.
Microsoft said its test period on iOS had expired, adding: "Unfortunately, we do not have a path to bring our vision of cloud gaming with Xbox Game Pass Ultimate to gamers on iOS via the Apple App Store."
It said all the games in its library are rated by games' rating bodies - such as the American ESRB (Entertainment Software Rating Board) - suggesting that Apple should not need to check each game again.
Apple "consistently treats gaming apps differently, applying more lenient rules to non-gaming apps even when they include interactive content," it said.
Strict rules about what can and cannot appear on the app store frequently cause problems between Apple and app developers.
The firm demands a 30% cut of all sales - including subscription sales - through its store, and recently became embroiled in a public row with an email app developer whom it threatened with removal from the store over subscription fees.
Apple's app store rules also ban any app with "a store-like interface", and explicitly only allows these types of apps if they are a "remote desktop" - a streaming copy of a device from far away.
That has been a problem for other gaming services in the past. Examples include Valve's Steam Link app, which displays a copy of the person's personal computer on a phone or tablet somewhere else in their home, or the Shadow gaming app, which gives users an entire remote computer to use.
A Shadow spokesperson told The Verge that it had originally found itself in a disagreement with Apple, and had to remove its "quick launch" feature that let users go straight into a game. Shadow had to remove that to become more like a "generic mirror" of a gaming computer to be approved, they said.
Microsoft says it is still committed to finding a way to bring its streaming service to Apple devices, despite there being no clear way to do so for now.