Myanmar's outgoing president Thein Sein (R) hands over the presidential seal to the country's new President Htin Kyaw (L) during the handover ceremony in Naypyidaw on March 30, 2016
Naypyidaw (Myanmar) (AFP) - Myanmar entered a new era on Wednesday as Aung San Suu Kyi's democracy movement took power after 50 years of military domination, with a close aide of the Nobel laureate sworn in as president.
Htin Kyaw, a school friend and confidant of the democracy champion, succeeds former general Thein Sein, who ushered in reforms that transformed Myanmar from a repressive hermit state to a nation full of hope.
As Htin Kyaw took the oath of office, he hinted he would change the army-imposed constitution that has excluded his friend and mentor from the top post.
Suu Kyi, 70, is barred from becoming president by the junta-scripted constitution but has declared that she will steer the government anyway. Htin Kyaw is expected to act as her proxy.
The handover at the junta-built parliament in the capital Naypyidaw marks the final act of a prolonged transition since Suu Kyi's National League for Democracy party swept elections last November.
The NLD won 80 percent of parliamentary seats, giving them a massive public mandate to rule.
They are tasked with reviving a battered economy and a society straitjacketed by the army, which ruled with an iron fist between 1962 and the start of reforms in 2011 under Thein Sein's quasi-civilian administration.
Welcoming a new age of full civilian government, the bespectacled new president pledged to be "faithful to the people of the republic of the union of Myanmar".
"I will uphold and abide by the constitution and its laws. I will carry out my responsibilities uprightly and to the best of my ability," the 69-year-old told the chamber.
- 'Democratic standards' -
In a later ceremony at the presidential palace, Thein Sein symbolically handed over to his successor as a smiling Suu Kyi looked on.
But the army is far from leaving the political scene. The military holds a quarter of all parliamentary seats and three key posts in the cabinet.
Suu Kyi, the standard-bearer of the fight for democracy, joins that same cabinet holding a clutch of positions including foreign minister.
In a speech later in the day Htin Kyaw signalled the NLD would continue its long-stated vow to amend the constitution to bring it up to "democratic standards" -- no small order given that the military's bloc in parliament gives it an effective veto on any such change.
He gave no details.
Expectations run high among Myanmar's 51 million people but the new government faces a steep task.
Revolts still rage in ethnic minority borderlands, poverty is widespread and the military holds huge political and economic power.
Sectarian tensions and anti-Muslim sentiment have flared in recent years.
US President Barack Obama hailed an "extraordinary moment" in Myanmar's history.
"Htin Kyaw’s inauguration represents a historic milestone in the country’s transition to a democratically elected, civilian-led government," Obama said in a statement.
But he warned of "significant challenges going forward," including on economic development and working to securing personal freedoms for all.
The European Union welcomed Htin Kyaw's swearing in as a "new important step in the consolidation of the country's remarkable transition".
But it added: "Many challenges remain for Myanmar to become an inclusive, pluralistic and peaceful democracy."
- 'Biggest day' -
NLD lawmakers also have little practical experience of government.
Some were jailed by the junta, including most famously Suu Kyi who was held under house arrest for s total of 15 years.
But on a historic day the party faithful were undaunted by the challenges ahead.
"I'm really happy. I am also remembering my colleagues who sacrificed for this battle (for democracy)," said NLD lawmaker Aye Naing.
Among a smattering of NLD supporters outside parliament, Yin Myint May welcomed the handover. "It is the biggest day for us," she said.
"Remember we started (the democracy fight) in 1990," she added, referring to elections won in a landslide by the NLD that were ignored by the junta.
Myanmar has witnessed a staggering political change since 2011 under Thein Sein.
Investors and tourists have begun to pile in as much repression has eased, promising a better future to a public who now have access to mobile phones, cheaper cars and other coveted consumer goods.
Hundreds of political prisoners have been released and media censorship lifted. Most western sanctions have been rolled back as a reward.
Suu Kyi's administration must still maintain smooth relations with the military that locked her and many of her colleagues up for years.
As well as their guaranteed parliamentary bloc, the junta charter gives the army chief control over the home affairs, border and defence ministries -- and with it sweeping powers over the civil service.