(CNN)Myanmar's President Htin Kyaw, one of the most loyal allies of the country's de facto leader Aung San Suu Kyi, is resigning due to ill health, according to the government. 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.