The announcement comes days after Altman was fired from OpenAI, a company he co-founded.

"We remain committed to our partnership with OpenAI and have confidence in our product roadmap, our ability to continue to innovate with everything we announced at Microsoft Ignite, and in continuing to support our customers and partners. We look forward to getting to know Emmett Shear and OAI's new leadership team and working with them.

"And we’re extremely excited to share the news that Sam Altman and Greg Brockman, together with colleagues, will be joining Microsoft to lead a new advanced AI research team. We look forward to moving quickly to provide them with the resources needed for their success," Nadella tweeted.

Nadella's post was shared by Altman with the message, "The mission continues."

In response to Altman's tweet, Nadella wrote: "I'm super excited to have you join as CEO of this new group, Sam, setting a new pace for innovation. We've learned a lot over the years about how to give founders and innovators space to build independent identities and cultures within Microsoft, including GitHub, Mojang Studios, and LinkedIn, and I'm looking forward to having you do the same,"

Speaking further on the decision to remove Sam, the firm said: "Altman’s departure follows a deliberative review process by the board, which concluded that he was not consistently candid in his communications with the board, hindering its ability to exercise its responsibilities. The board no longer has confidence in his ability to continue leading OpenAI."

Last week, Open AI sacked CEO Sam Altman prompting the co-founder Greg Brockman to quit soon after.

The company said OpenAI's Chief Technology Officer Mira Murati will serve as the interim CEO.

"The board of directors of OpenAI, Inc., the 501(c)(3) that acts as the overall governing body for all OpenAI activities, today announced that Sam Altman will depart as CEO and leave the board of directors. Mira Murati, the company’s chief technology officer, will serve as interim CEO, effective immediately," the tech firm said in a statement.