The military justified its February 2021 putsch with unsubstantiated claims of widespread fraud in 2020 elections won resoundingly by Aung San Suu Kyi's National League for Democracy (NLD).
The coup ended a 10-year democratic experiment and plunged the country into turmoil, with the military now battling opponents across swathes of the country.
"Elections are likely to be held in 2025," a senior member of the military-backed Union Solidarity and Development Party told AFP, requesting anonymity.
"We have a census-taking process in 2024. Because of the situation (in Myanmar) and that nationwide census process, next year is impossible," they said.
A member of a junta-approved party said it was likely "elections will be held in early 2025", without elaborating.
Thirty-six political parties have been granted permission to take part in any future polls, the junta-stacked election commission said Tuesday, without giving a date for when they would be held.
Seven had been approved to compete countrywide, and 29 on a regional level.
It also announced the first-past-the-post system - under which the NLD won crushing majorities at the expense of military-backed parties - would be scrapped.
A proportional representation system would be used across the country, it said.
In March the election commission dissolved the NLD for failing to re-register under tough new military-authored rules.
Aung San Suu Kyi co-founded the NLD in 1988, and won a landslide victory in 1990 elections that were subsequently annulled by the then-junta.
The party carried the torch for democratic aspirations in military-ruled Myanmar and later won big victories over military-backed parties in elections in 2015 and 2020.
Its leadership has been decimated in the junta's bloody crackdown on dissent, with one former lawmaker executed by the junta in the country's first use of capital punishment in decades.
The junta accepts it does not control swathes of the country and has previously pushed back the timeline for holding polls.
"It's highly uncertain if and when polls will take place, there is no discernible timetable," independent analyst David Mathieson told AFP.
"It shouldn't have to be reemphasised, but any poll any time under whatever conditions will be bereft of legitimacy and meaning."
Junta chief Min Aung Hlaing called for "necessary preparations" to be completed ahead of the national census in 2024, the state-backed Global New Light of Myanmar reported on Saturday.
An election can only take place after a census has been completed, the paper reported him as saying.
The United States has said any elections under the junta would be a "sham" and analysts say they would be targeted by the junta's opponents.
Russia, a major ally and arms supplier, has said it backs the plan for polls.
Khin Yi, chairman of the military-backed Union Solidarity and Development Party said his party was preparing for a future election.
"There have been threats," Khin Yi told AFP, without elaborating.
"However I'm moving forward ... This time is the period to motivate our party."
The army ruled Myanmar for decades after independence from Britain in 1948, and dominated the country's economy and politics even before the coup.
Myanmar remains mired in almost daily bomb blasts and fighting, with thousands of civilians caught up in the violence.