Myanmar's junta chief, flanked by tanks and missile launchers, vowed no let up in a crackdown on opponents and said Monday elections would be held, weeks after the military conceded it did not control enough territory to allow a vote.

Myanmar has been in turmoil since the military deposed Aung San Suu Kyi's civilian government more than two years ago after making unsubstantiated claims of electoral fraud.

The putsch sparked renewed fighting with ethnic rebels and birthed dozens of anti-junta "People's Defence Forces" (PDFs), with swaths of the country now ravaged by fighting and the economy in tatters.

The military will take "decisive action" against its opponents and ethnic rebels supporting them, Min Aung Hlaing told an audience of around 8,000 service members attending the annual Armed Forces Day parade in the capital Naypyidaw.

"The terror acts of NUG and its lackey so-called PDFs need to be tackled for good and all," he said, referring to the "National Unity Government", a body dominated by ousted lawmakers working to reverse the coup.

The junta would then hold "free and fair elections" upon the completion of the state of emergency, he said.

The military announced last month a six-month extension of a two-year state of emergency and postponed elections it had promised to hold by August because it did not control enough of the country for a vote to take place.

"Serenity and stability are vital" before any election could go ahead, Min Aung Hlaing told the parade.

- Russian jets -

Armed Forces Day commemorates the start of resistance to the Japanese occupation during World War II. It usually features a military parade attended by foreign officers and diplomats.

Workers made last-minute inspections of the parade ground early on Monday, the hulking statues of three of Myanmar's empire-building kings looming out of the dark.

Planes later trailed smoke in the yellow, red and green of the national flag as Russian-made Yak and Sukoi Su-30 jets made several flyovers.

Marching bands played bagpipes and brass, at times duelling with each other, and state media images showed women lining the streets to garland marching soldiers with flowers.

New junta chief Min Aung Hlaing was inspecting the parade two years ago when troops launched a countrywide crackdown on those protesting against the coup that had ousted Suu Kyi's government.

Around 160 protesters were killed in the violence, according to a local monitoring group, sparking widespread international condemnation.

Rights groups and opponents have since accused the military of torching villages and using air and artillery strikes as collective punishment for opponents.

Min Aung Hlaing slammed the "criticism and condemnation" levelled at the junta, accusing some countries of supporting terrorists.

Officials from major junta allies and arms suppliers Russia and China attended, and India also sent a representative.

New Delhi has defended its ties with the junta, saying India cannot avoid dealing with its neighbour because of cross-border issues such as organised crime.

The United States announced on Friday new sanctions targeting the supply of jet fuel to the junta.

The situation in Myanmar is a "festering catastrophe" two years after the coup, United Nations human rights chief Volker Turk said this month, adding that the military was operating with "complete impunity".

Diplomatic efforts to defuse the bloody crisis, led by the Association of Southeast Asian Nations, have made little progress.

A Myanmar official said seven countries from the 10-nation bloc sent representatives to the parade, including Malaysia and Indonesia, who are among the group's most vocal critics of the junta.

More than 3,100 people have been killed in the military's crackdown on dissent since the coup, according to a local monitoring group.

More than a million people have been displaced by fighting, according to the United Nations.

The junta wrapped up a series of closed-court trials of Suu Kyi in December, jailing her for a total of 33 years in a process rights groups have condemned as a sham.