The United States lifted sanctions on two of Myanmar's top leaders on Wednesday, as the Congress hailed Aung San Suu Kyi as a hero of democracy in a lavish ceremony unthinkable only months ago.
The move to end the sanctions on Myanmar President Thein Sein and parliamentary speaker Thura Shwe Mann came just hours after Suu Kyi had called for US sanctions crippling her impoverished nation to be lifted.
She also met fellow Nobel Peace laureate President Barack Obama for the first time, after being presented with the Congressional Gold Medal in the imposing surroundings of the historical Rotunda on Capitol Hill.
In a statement, the White House said Obama reaffirmed US support for political and economic reforms in Myanmar, and full protection of the fundamental rights of its people, in order to shape "a more peaceful, free and prosperous future" for the country.
Myanmar was ruled by an iron-fisted junta for decades but, since taking office last year, a reformist government under former general Thein Sein has freed political prisoners and allowed Suu Kyi's party into electoral politics.
"From the depths of my heart I thank you, the people of America... for keeping us in your hearts and minds during the dark years when freedom and justice seemed beyond our reach," Suu Kyi said, as she was handed the award.
Amid the changes sweeping her Southeast Asian nation, the Nobel Peace Prize laureate said: "We believe that we can go forward in unity and in peace."
"There will be difficulties in the way ahead, but I'm confident that we shall be able to overcome all obstacles with the help and support of our friends," Suu Kyi added.
The US Treasury later dropped both Thein Sein and Shwe Mann from its list of "Specially Designated Nationals" sanctioning individuals and companies for links to terrorism, narcotics or other crimes.
The two men "have taken concrete steps to promote political reforms and human rights, and to move Burma away from repression and dictatorship toward democracy and freedom, warranting today's delisting action," Treasury Under Secretary for Terrorism and Financial Intelligence David Cohen said in a statement.
They had been placed on the list in 2007 as the US raised pressure on the then ruling military junta, in which Thein Sein served as first secretary and Shwe Mann was joint chief of staff of the armed forces.
Freed in 2010 after 15 years of under house arrest, Suu Kyi received a rapturous welcome on her first visit to Washington since her release.
"It's almost too delicious to believe, my friend, that you are here in the rotunda of our great Capitol, the centerpiece of our democracy, as an elected member of your parliament," Secretary of State Hillary Clinton said.
But, addressing the ceremony, Clinton said a different phase of Suu Kyi's work was just beginning as she helps build democracy in Myanmar.
"The United States will stand with her, with the president of Burma and those who are reformers... as they fan the flickers of democratic progress and press forward with reform," the top US diplomat vowed.
Suu Kyi was also praised by veteran Republican Senator John McCain who, in a moving speech, called her "my personal hero."
"I want to thank you... for teaching me, at my age, a thing of two about courage," said McCain, 76, who spent more than five years in the notorious "Hanoi Hilton" as a prisoner of war during the Vietnam war.
Suu Kyi's own remarks, from a podium flanked by six US flags and white marble statues of Abraham Lincoln and US civil war general Ulysses S. Grant, were bookended by a standing ovation.
The Obama administration has taken pains to ensure the celebration around her visit does not detract from a simultaneous trip to the United States by Thein Sein, who ushered in the reforms much to global surprise.
US officials say Thein Sein -- who will take part in the UN General Assembly next week -- deserves to be recognized for pushing through such speedy changes.
The United States began rolling back its economic embargo in July, opening Myanmar up to US investment despite Suu Kyi's earlier unease about US firms doing business with the state-owned oil and gas company.
"There are very many other ways in which the United States can help us to achieve our democratic ends and help us to build up the kind of democratic institutions that we are in such need of," Suu Kyi said on Tuesday. "Sanctions are not the only way."
Many US observers say Thein Sein launched the reforms out of concern over Beijing's overwhelming political and economic dominance in Myanmar.
Clinton, however, has also called for Myanmar to address tensions in Rakhine state, where recent violence between majority Buddhists and the Muslim Rohingya minority left scores dead and displaced tens of thousands of people.
Suu Kyi has come in for rare criticism from human rights activists, who have pressed her to speak out on behalf of the 800,000-strong Rohingya population.