WASHINGTON (AP) -- Two years after the United States announced the normalization of diplomatic relations with Myanmar, optimism in Washington over the nation's embrace of democracy is waning and concern over the plight of minority Muslims is growing.
What has been viewed as a foreign policy success story for the Obama administration, supported by both Democrats and Republicans, faces a rocky road ahead as the pace of political reform slows and U.S. congressional criticism intensifies.
Lawmakers are frustrating the administration's efforts to engage the nation's powerful military, and antipathy will likely increase if opposition leader Aung San Suu Kyi, long revered in Washington, is unable to run for the presidency next year and complete a Mandela-like transformation from former political prisoner to head of state.
Suu Kyi is ineligible to be president because she was married to a foreigner.
While the United States says it remains hopeful the constitution can be amended so Suu Kyi can run, congressional aides say the administration is pessimistic about that happening before the national elections at the end of 2015, a key staging post in Myanmar's transition from five decades of repressive army rule. Constitutional reforms would also be required to dilute the political power of the military and meet ethnic minority demands for autonomy. The aides weren't authorized to discuss that matter and spoke on condition of anonymity.
But the most pressing concern for the U.S., and the one on which the Obama administration and lawmakers have been most outspoken, is communal violence between majority Buddhists and Muslims, and the rising tide of Buddhist nationalism that many expect to intensify in the run-up to the election.
The House Foreign Affairs Committee called last week for an end to persecution of stateless Rohingya Muslims in one of the strongest congressional criticisms yet of Myanmar's reformist government. The committee's Republican chairman, Rep. Ed Royce of California, questioned whether the U.S. should embrace diplomatic reconciliation with Myanmar while human rights deteriorate.
Myanmar, also known as Burma, regards Rohingya as illegal immigrants from Bangladesh, although many have lived in Myanmar for generations. Some 140,000 Rohingya displaced by the violence since mid-2012 live in overcrowded, dirty camps that segregate them from Buddhists. Tens of thousands of Rohingya have fled the country by boat.
A month ago Myanmar suspended the operations of Doctors Without Borders, the main health care provider in the strife-hit state of Rakhine. Other relief agencies fled this week because of attacks by Buddhist mobs that the United Nations said threatened the entire humanitarian response in the state.
State Department spokeswoman Marie Harf on Wednesday voiced deep concern about the "humanitarian crisis" there.
"Currently, large segments of the population do not have access to adequate medical services, water, sanitation and food. The government has so far failed to provide adequate security and the travel authorizations necessary for the humanitarian aid workers to resume their lifesaving services," she said.
That strong statement came almost two years to the day that then-Secretary of State Hillary Rodham Clinton announced the U.S. was appointing its first full ambassador to Myanmar in two decades, ending a policy of diplomatic isolation. That rewarded the fair conduct of special elections in which Suu Kyi won a parliamentary seat.
By November 2012, the U.S. had suspended most of its restrictions on aid, trade and investment, and Barack Obama became the first U.S. president to visit Myanmar -- hugging Suu Kyi outside the lakeside villa where she was once imprisoned.
Obama's visit crowned a rapid transformation in relations, and U.S. officials say they remain optimistic about Myanmar's path. They point to the release of hundreds of political prisoners, economic reforms and easing of restrictions on media and labor unions. The government is also trying to reach peace with armed ethnic groups that have fought central rule since independence in 1948.
A U.S.-funded poll released Thursday by the International Republican Institute found that 88 percent of respondents sampled across Myanmar thought things in the country were heading in the right direction, and 57 percent thought their economic situation was going to improve in the coming year. The margin of error is plus or minus 2 percentage points.
In the latest diplomatic landmark, Defense Secretary Chuck Hagel this week hosted Myanmar's defense minister at a gathering of top Southeast Asian defense officials in Hawaii.
The administration views military engagement as a way of getting Myanmar's army to adopt international norms, and there's support among lawmakers who oversee defense policy for that approach, starting with nonlethal U.S. training of Myanmar's military on human rights, rule of law and disaster relief.