Pictures widely shared on social media showed a shaven-headed Thein Sein wearing his trademark spectacles and draped in the deep maroon robes of the Buddhist clergy.

Myanmar language state newspaper Myanma Alinn said he had entered a monastery in the central town of Pyin Oo Lwin on Monday for a five-day stint, taking the monk title "U Thandidamma".

"Those close to U Thein Sein said he will practice meditation during a temporary monkhood of about five days," the paper said.

It added that he had promised Buddhist elders he would be ordained as a monk once he finished his role as president.

Thein Sein, a former junta general, led Myanmar's quasi-civilian transitional government through five stunning years of reform, as the nation opened up to the world after decades of repressive and isolating army rule.

Only a few years earlier the junta led a violent crackdown on largely monk-led protests that were dubbed the "Saffron Revolution".

The unobtrusive 70-year-old handed power to Suu Kyi and her proxy president Htin Kyaw last week.

While not in parliament he is expected to continue to lead his army-backed party, now in opposition after Suu Kyi's party won landmark November polls in a landslide.