Microsoft chief executive Satya Nadella says that his company remains in the mobile phone business but any new devices will have to bring something different to the table, in terms of form factor, usability and security.

Speaking to The Australian Financial Review, Mr Nadella did not directly comment on persistent rumours that the company is poised to unveil a new line of phones under the Surface brand.

These rumors emerged last year after Microsoft took a $US7.6 billion write-down on the Nokia handset business it had acquired under Mr Ballmer, and scaled back its attempts to crack the consumer smartphone market.

Mr Nadella, however, said the company was not going to launch into a device category without bringing something different to the table, and was more interested in how individuals and organizations were using devices, than the devices themselves.

"We don't want to be driven by just envy of what others have, the question is, what can we bring? That's where I look at any device form factor or any technology, even AI," he said.

Commenting on HP's Elite x3 device, which is part smartphone and part mini Windows PC, Mr Nadella said Microsoft was already present in "structural innovation" in the phone arena, and was focusing on productivity, management and security in mobile.

"We will continue to be in the phone market not as defined by today's market leaders, but by what it is that we can uniquely do in what is the most ultimate mobile device," he said.

"Therefore [with Nokia assets], we stopped doing things that were me-too and started doing things, even if they are today very sub-scale, to be very focused on a specific set of customers who need a specific set of capabilities that are differentiated and that we can do a good job of."

Microsoft is rumored to enable x86 on ARM64 emulation in Windows 10 by Fall 2017 with its 'Redstone 3' update release.