Htin Kyaw's resignation comes as international pressure increases on Nobel Laureate Suu Kyi to do something to ease the suffering of the country's minority Rohingya population.
Long-time friend
A close friend and confidante of Suu Kyi, Htin Kyaw served as an executive officer for the Daw Khin Kyi Foundation, a charitable organization named after Suu Kyi's late mother. His father-in-law was also active in the establishment of the NLD.
He was one of a handful of people allowed to visit her while she was under house arrest, studied alongside her in England, and was close to her husband.
The economics graduate was elected in 1990 as a parliament executive of the NLD, and assumed the role of president after the party swept national elections, taking around 80% of the available seats, in November 2015.
Htin Kyaw was elected to the position of President by 360 votes, more than a third of the parliament's available 652 votes.