YANGON, Myanmar -- Myanmar has changed dramatically over the last year, but one thing won't change anytime soon: the country's name.

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.

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  • In this June 16, 2012, file photo, Aung San Suu Kyi delivers a speech during the Nobel ceremony at Oslo's City Hall, Norway. (AP Photo/Daniel Sannum Lauten/Pool, File)

  • Myanmar opposition leader Aung San Suu Kyi visits the Nobel Peace Center in Oslo, Norway, Saturday, June 16, 2012. (AP Photo/Cathal McNaughton, Pool)

  • In this June 21, 2012, file photo, Myanmar opposition leader Aung San Suu Kyi, left, Britain's Prince Charles, center, and Camilla Duchess of Cornwall react after planting a Magnolia tree in the gardens of Clarence House, in London. (AP Photo/Facundo Arrizabalga, Pool, File)

  • In this June 20, 2012, file photo, Myanmar opposition leader Aung San Suu Kyi, poses for the photographers following an award ceremony at the Oxford University, Oxford, England. (AP Photo/Lefteris Pitarakis, File)

  • Myanmar opposition leader Aung San Suu Kyi makes an address to a joint session of both Houses of Parliament, in Westminster Hall, in London, Thursday June 21, 2012. (AP Photo/Dominic Lipinski, Pool)

  • In this June 18, 2012, file photo, Irish singer Bono hands Myanmar opposition leader Aung San Suu Kyi the Amnesty International's Ambassador of Conscience award in Dublin, Ireland. (AP Photo/Alastair Grant, File)

  • In this July 26, 2012, file photo, Myanmar opposition leader Aung San Suu Kyi, left, and French President Francois Hollande walk in the Elysee Palace garden in Paris. (AP Photo/Bertrand Langlois, Pool, File)

  • Myanmar opposition leader Aung San Suu Kyi speaks during a debate with French students at the Sorbonne University, in Paris, Thursday June 28, 2012. (AP Photo/Thibault Camus)

  • Myanmar opposition leader Aung San Suu Kyi greets classical singer Mar Mar Aye, right, during a meeting with members of the Myanmar community at the Royal Festival Hall in central London, Friday June 22, 2012. (AP Photo/Suzanne Plunkett, Pool)

  • In this photo taken Tuesday, June 19, 2012, and released by the Office of His Holiness the Dalai Lama, Tibetan spiritual leader the Dalai Lama, left, speaks to Myanmar opposition leader Aung San Suu Kyi during their private meeting in London. (AP Photo/Jeremy Russell, Office of His Holiness the Dalai Lama)