WASHINGTON (AFP) - Myanmar President Thein Sein on Monday becomes the first leader of his country to visit the White House in nearly half a century, in one of the most symbolic US gestures yet to support his reforms.
In a scene that would have been unimaginable just a few years ago, the former general will meet with President Barack Obama and later speak to leaders of US businesses eager to invest in a country that was long a Western pariah.
Critics say that President Barack Obama's invitation was premature and takes pressure off Myanmar to address still-alarming abuses such as recent anti-Muslim violence to which security forces allegedly turned a blind eye.
Mr Thein Sein, who took office as a nominal civilian in 2011, surprised even cynics by freeing hundreds of political prisoners, easing censorship and letting long-detained opposition icon Aung San Suu Kyi enter parliament.
Mr Obama - whose 2009 inaugural speech pledge to reach out to US foes yielded limited results in the Middle East - has been enthusiastic about Myanmar. He visited in November and has suspended most sanctions in recognition of changes.
The White House said in a statement that Mr Thein Sein's visit "underscores President Obama's commitment to supporting and assisting those governments that make the important decision to embrace reform."
Mr Zaw Htay, director of Thein Sein's office, welcomed US support and rejected fears that the country will slide back. Myanmar freed another 20 political prisoners last week, although activists say some 200 more remain in jail.
"Myanmar's Spring is more concrete than the Arab Spring. This spring represents the values that the US has been promoting around the world," he told AFP.
The most critical test will come in 2015, when Myanmar is scheduled to hold elections - testing whether the military and its allies would be willing to cede power, potentially to Ms Suu Kyi.
The army seized control of the country then known as Burma in 1962, ushering in decades of isolation. Military ruler Ne Win in 1966 was the last leader to visit the White House, where he met president Lyndon Johnson.
Many experts believe that a key motivating factor for Myanmar's reforms was to ease its dependence on neighboring China, which developed an overwhelming influence in the proudly independent country amid US and European sanctions.
The United States has pushed ahead on new efforts to show tangible benefits for the reform path.
In a move long sought by the rulers, the United States increasingly calls the country Myanmar, while officially sticking to the name Burma favoured by exile groups.
In recent weeks, the United States ended sweeping restrictions on visas and top trade official Demetrios Marantis visited Myanmar to start discussions on economic measures such as offering duty-free access for certain products.
But in a signal ahead of Mr Thein Sein's visit, Representative Joe Crowley, who has long been active on Myanmar, introduced legislation to extend for one year a ban on the country's gems - a key money-maker for the military.
Mr Crowley, a member of Obama's Democratic Party from New York, said he was "very concerned" about human rights violations in Myanmar including "brutal attacks" in recent months against the Muslim minority.
A recent Human Rights Watch report accused Myanmar of a "campaign of ethnic cleansing" against the Rohingya, a mostly Muslim minority who are not even considered citizens of the predominantly Buddhist nation.
The US Campaign for Burma, an advocacy group that plans protests against Thein Sein, said that the United States should have retracted or at least frozen gestures toward Myanmar as a condition to stop abuse of the Rohingya.
"President Obama is sending the message that crimes against humanity by state forces against ethnic and religious minorities in Burma will be ignored by his administration," said Jennifer Quigley, the group's executive director.
Administration officials contend that Thein Sein has made sincere efforts to address ethnic and sectarian violence, whose roots predate his tenure.