President Thein Sein's historic invitation to the White House is an endorsement of "Myanmar's Spring" and a further sign that the former pariah's reforms are irreversible, a senior Myanmar official said.
Washington will welcome the former general on Monday in a hugely symbolic reward for sweeping changes since he took power two years ago. He will be the first leader of the former military-ruled nation to visit since 1966.
But the trip comes amid heightened concerns over the direction and durability of Myanmar's democratic reforms, in particular following several outbreaks of deadly communal and religious violence.
In an interview with AFP from the capital Naypyidaw, Zaw Htay, director of Thein Sein's office, said his country would not backtrack on its path towards democracy.
"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 said.
He hailed the "momentum" of the reforms as well as warming Myanmar-US ties since President Barack Obama's own visit to Myanmar in November.
Thein Sein's trip shows "US support for the president's leadership and his reform process," he said.
"The US worries how firm our country's steps towards democracy will be and whether we may go backwards or not," he added.
"President (Thein Sein) has firmly stated that he will never go backwards."
Thein Sein's government had warned earlier he might delay his departure depending on Cyclone Mahasen, but officials said Friday he would go ahead with the visit after the storm sparred Myanmar from major damage.
He was due to leave Myanmar late on Friday and return next Thursday, a Myanmar government official who did not want to be named told AFP.
The former junta premier came to power in March 2011 in the wake of elections marred by widespread allegations of fraud and intimidation.
Under his leadership, Myanmar has released hundreds of political prisoners, eased censorship, taken steps to open the economy and allowed opposition leader Aung San Suu Kyi -- a Nobel peace laureate who spent most of the past two decades under house arrest -- to enter parliament.
Ahead of his departure to the US, Myanmar on Friday freed about 20 more political prisoners, in a move Zaw Htay later said showed the president's determination to have an "inclusive political process".
Activists say some 200 political prisoners remain in jail and accuse Myanmar of using a series of headline-grabbing amnesties for political gain.
Rights groups have also decried recent anti-Muslim violence and accused the security forces of failing to stop -- or even supporting -- sectarian attacks.
A recent Human Rights Watch report accused the country of a "campaign of ethnic cleansing" against Muslim Rohingya, a minority group who are not even considered citizens of the predominantly Buddhist nation.
The White House on Thursday said Obama would offer US help in the "many remaining challenges to efforts to develop democracy, address communal and ethnic tensions and bring economic opportunity" in Myanmar.
The trip is part of Washington's diplomatic drive -- launched in 2009 -- to reward reforms in the resource-rich and strategically significant nation, which borders China.
The Obama administration has suspended most sanctions against Myanmar as it seeks to encourage the changes and extend its influence in the long-isolated nation.
Zaw Htay said Washington had much to offer Myanmar in terms of assistance developing security, rule of law, education, health and poverty reduction.
"We hope that those matters can be discussed and implemented during the president's White House visit," he said.
He added that Thein Sein also hoped to win over sceptical members of the US Congress, whose support is needed for the end of the remaining US sanctions.
"We need Congress to see and understand the difficulties we are facing in our reform steps," he said.
Thein Sein is also due to speak at Johns Hopkins University's School of Advanced International Studies and the US Chamber of Commerce, the country's largest business federation, according to the two organisations.