Authorities in the Southeast Asian nation sternly warned opposition leader Aung San Suu Kyi on Friday to stop calling the country "Burma." They said she should use the constitutionally decreed title, the Republic of the Union of Myanmar.

Its then-military rulers changed the English name from Burma to Myanmar in 1989, ostensibly to better reflect the country's ethnic diversity. The term Burma connotes Burman, the dominant ethnic group in the country, to the exclusion of ethnic minorities. But regime opponents and exile groups from a range of ethnicities - as well as foreign governments including the United States - have persisted in calling the country Burma in protest and defiance against an undemocratic regime they long saw as illegitimate.

Myanmar's election commission, which supervises laws dealing with political parties, issued the complaint in the state-run New Light of Myanmar newspaper. The statement cited Suu Kyi's repeated references to the country as Burma during her landmark trips in recent weeks to Thailand and Europe, and it said she and her National League for Democracy Party must "respect the constitution" and use the proper name.

It's not clear whether there are any legal consequences for not doing so.

A former political prisoner, Suu Kyi became a lawmaker after her party won dozens of parliament seats in April by-elections, a vote that was symbolic of the post-junta changes that have swept the country under the leadership of President Thein Sein. Weeks later, she and her opposition colleagues took the oath of office, which includes an official vow to uphold the constitution.

Suu Kyi's party spokesman Nyan Win said the election commission's complaint was a non-issue. "Referring to the country as Burma does not amount to disrespecting the constitution," he said.

In the official state language, the country and its people are both pronounced Myanmar.