Stephen Elop, speaking during an investor call, said that a Windows Phone from Microsoft would be a "stimulant to the ecosystem," according to The Verge.
"We're encouraging of HTC and Samsung and Microsoft or whomever to have devices in the market and to be making whatever investments that helps spur the ecosystem on," Elop said, according to the report.
Rumors have been circulating for months that Microsoft was going to make its own Windows Phones and possibly market them under the Surface brand. Such a move has been viewed as a threat to Nokia, Microsoft's premier phone partner. Unlike other smartphone makers, which typically also make Android devices, Nokia has placed its bets on Windows Phone.
Elop today said the Nokia's research and development labs have "unpolished gems" it can use to differentiate its phones, no matter who its competition is.
"We're very proud of the unique differentiation that we are bringing to the Windows Phone platform," he added. "It's not something that's easily replicated or reinvented or anything like that."
When Microsoft unveiled its Surface tablet, it angered its PC partners. Microsoft didn't notify its chip or computer allies much in advance of the launch, and it's believed that Microsoft developed Surface partly because it was worried about the quality of its partners' devices.
Making a phone would be a departure from Microsoft's current mobile phone efforts, which so far has left the design and creation of Windows Phone handsets to its hardware partners. Those partners, like Nokia and HTC, work off a reference design and list of hardware requirements. Such devices have typically been met with fairly positive reviews.