Map of Southeast Asia, denoting Burma (top middle).
Myanmar or Burma was an Earth nation-state.
History and specifics
On 10 July 1992 at his palace citadel in Chandigarh, India, Khan Noonien Singh announced his annexation of Myanmar into the Great Khanate, along with Bangladesh, Bhutan, Cambodia, Indonesia, Malaysia, Nepal, Pakistan, Singapore, Sri Lanka, Thailand, and Vietnam. (TOS - The Eugenics Wars novel: The Rise and Fall of Khan Noonien Singh, Volume 2)
Kelvin timeline
According to Khan Noonien Singh, in September 1992 Burma was part of Australasia, which was annexed by Augment Dictator Bernard Maltuvis. Australasia then became known as Maltuvisland until the Augment dictatorships were overthrown in 1996. (TOS - Khan comics: "Issue 2", "Issue 3")