https://arstechnica.com/gadgets/2018/04/tim-cook-on-merging-macos-and-ios-i-dont-think-thats-what-users-want/

In an interview published in The Sydney Morning Herald today, Apple CEO Tim Cook suggested that Apple is not working toward eventually running the same operating system on Macs and mobile devices like the iPhone and iPad, counter to widespread speculation.

The interview took place at the education-themed event in Chicago at which Apple unveiled the last iPad. Here's the relevant quote from Cook: