Myanmar's military seized control of the country on Monday and detained leading politicians, including Nobel Laureate Aung San Suu Kyi.
The army declared a state of emergency for one year, accusing authorities of failing to resolve allegations of fraud in November's electiion.
Commander-in-chief Senior General Min Aung Hlaing said new elections would be held, but he gave no time frame.
He pledged to practice "the genuine discipline-flourishing multiparty democratic system" in a fair manner.
World powers, including the United States, condemned the coup and called for elected leaders to be released.