Myanmar President Thein Sein and the powerful army congratulated democratic champion Aung San Suu Kyi on Wednesday, after her party trounced the ruling camp in the first free election in 25 years and was closing in on an absolute majority in parliament.

Thein Sein reiterated that the government would accept the results of the election and agreed to Suu Kyi's request to hold reconciliation talks soon, although the two are still to agree on the time and location of the negotiations.

Suu Kyi's opposition National League for Democracy (NLD) has won over 80% of the seats declared so far in the lower house and is well ahead in the upper house and regional assemblies.

If the final results confirm the trend, Suu Kyi's triumph will sweep out an old guard of former generals that has run Myanmar since the junta handed over power to Thein Sein's semi-civilian government in 2011.

Such unambiguous endorsement of Suu Kyi's victory could smooth the post-election transition, ahead of the first session of parliament which reconvenes on Monday.

"Congratulations to the chairperson Aung San Suu Kyi and her party for gathering the support of the people," read a statement posted on the Facebook page of the presidential spokesman.

"The government will respect and follow the people's choice and decision, and work on transferring power peacefully according to the timetable," said the statement, adding that the president would work with "all other people" to ensure stability in the post-election period.

The army has also congratulated the NLD on its win in a statement posted to the Facebook page of the military's media portal, Myawady.

The armed forces continue to wield considerable power in Myanmar's political institutions, under a constitution drafted before the end of nearly 50 years of rule. It is unclear how Suu Kyi and the generals will work together.

Relations between Suu Kyi and armed forces Chief Min Aung Hlaing are said to be strained.

"We would like to congratulate the National League for Democracy because it is leading in the election results," the army said in the statement.

It also said that the army chief would meet Suu Kyi for reconciliation talks after official results are out.

One of the biggest sources of tension between Suu Kyi and the military is a clause in the constitution barring her from the presidency because her children are foreign nationals.

Few doubt the military inserted the clause to rule her out.

'MAKING ALL DECISIONS'

While her letters seek conciliation, Suu Kyi has become increasingly defiant on the presidential clause as the scale of her victory has become apparent.

The ruling Union Solidarity and Development Party (USDP), created by the junta and led by retired soldiers, has conceded defeat in a poll that was a major milestone on Myanmar's rocky path from dictatorship to democracy.

In addition to his bloc of parliament seats, the commander-in-chief nominates the heads of three powerful and big-budget ministries - interior, defence and border security.

The interior ministry gives him control of the pervasive bureaucracy, which could pose a significant obstacle to the NLD's ability to execute policy.

Among other formidable challenges for Suu Kyi is trying to put an end to decades of conflict with armed ethnic groups.

Thein Sein failed to do that despite protracted talks that led to a ceasefire with some groups. The government's chief ceasefire negotiator, Aung Min, was among the heavyweight politicians that lost in the elections.

Sunday's vote was Myanmar's first freely contested general election since Thein Sein ushered in a period of reforms that prompted a partial lifting of international sanctions.

Money from abroad flowed in quickly afterward. Foreign direct investment stood at $8 billion in fiscal 2014/15, more than five times the flows recorded just two years earlier.

Washington welcomed the election as a victory for Myanmar's people, but said it would watch how the democratic process moved forward before lifting the remaining U.S. sanctions.

Final results are due no later than two weeks after Sunday's poll.