The military junta that has controlled Myanmar for decades was disbanded on Wednesday after widely-criticized elections installed a civilian government featuring many of the same faces.
State media reported that Thein Sein, an ex-general and the junta's former prime minister, was sworn in as president in a ceremony held behind closed doors in the secretive country's remote capital, Naypyitaw.
Myanmar, also known as Burma, held its first elections in 20 years last November after committing to democratic reforms in the face of international pressure.
The vote, which was boycotted by Nobel-winning democracy campaigner Aung San Suu Kyi, was marred by claims of cheating and voter intimidation.
Two new vice-presidents — Tin Aung Mying Oo and Sai Mauk Hkam — also took their oaths in Wednesday's ceremony, AFP said.
Min Aung Hlaing, was named as the new commander of Myanmar's armed forces, replacing Than Shwe, the strongman who has held sway over Myanmar for much of the military's half-decade rule over the country.
There was no mention of the 78-year-old at Wednesday's ceremony, but there were claims he would be remain a powerful figure behind the scenes.
Under the country's constitution, the new parliament must feature 100 military nominees. The Associated Press said the 30-member Cabinet is also dominated by former military officers, with only four fully civilian appointees.
Suu Kyi, who won elections in 1990 but was prevented from taking power and eventually placed under long-term house arrest, said she hoped her opposition National League for Democracy would have a better dialogue with the new leadership.
"We always want good relations with the government. I hope that the relationship improves," she said, according to AP. "We will work for good relations."
-- Barry Neild