NAYPYIDAW, Myanmar (AP) ― Looking to cement a foreign policy success and prod democratization in one of the world’s most isolated and authoritarian nations, U.S. Secretary of State Hillary Rodham Clinton sought Thursday to test the willingness of Myanmar’s leaders to expand nascent reforms.

On a historic visit here, Clinton said she was hopeful, but not yet convinced, that “flickers of progress” in the Southeast Asian country will burst into flames of change.

Clinton, speaking to Myanmar’s President Thein Sein during their meeting, said: “I am here today because President Obama and myself are encouraged by the steps you and your government have taken to provide for your people.”

Sein said Clinton’s visit was a historic chapter in relations between the two nations. Their meeting took place in a grandiose palace that has 40-to-60 foot ceilings, chandeliers and teak doors. It is situated near a virtually empty, 20-lane highway.

Clinton’s diplomatically risky trip to a nation that receives few outsiders and still heavily restricts what its people can see and read is meant to test whether new civilian leaders are truly ready to throw off 50 years of military dictatorship. U.S. officials said she would also press the leadership on severing military and suspected nuclear ties with North Korea.

“I am obviously looking to determine for myself and on behalf of our government what is the intention of the current government with respect to continuing reforms both political and economic,” Clinton told reporters before her arrival here. Hers is the first trip by a U.S. secretary of state to the country also known as Burma in more than half a century.

She was meeting senior Myanmar officials, including the president, the foreign minister and top lawmakers, in the capital Naypyidaw on Thursday before heading to the commercial capital of Yangon. There she will see opposition leader and Nobel peace laureate Aung San Suu Kyi, who is returning to the political scene after decades of detention, harassment and violent repression.

Successive military regimes canceled 1990 elections that Suu Kyi’s National League for Democracy party won. She has said she plans to run in upcoming elections.

“We and many other nations are quite hopeful that these flickers of progress ... will be ignited into a movement for change that will benefit the people of the country,” Clinton said. President Barack Obama used the same description ― “flickers of progress” ― when he announced he was sending Clinton to Myanmar.

Clinton was greeted at Naypyidaw’s small airfield by a deputy foreign minister, several other officials and a large contingent of international press who were granted rare visas to cover her visit. But her presence here appeared to take second stage to the expected arrival Thursday of the prime minister of Belarus and his wife, to whom two large welcoming signs were erected at the airport and the road into the city. Belarus is often criticized for its poor human rights record and is subject to U.S. sanctions similar to those Myanmar is under.

No signs welcoming Clinton were visible as her motorcade bounced from the airport to the city on a bumpy cement road that was largely devoid of vehicles, with traffic police stopping small and scattered groups of cars, trucks and motorbikes at intersections.

Officials say Clinton will be seeking assurances from Myanmar’s leaders that they will sign an agreement with the U.N. nuclear watchdog that will permit unfettered access to suspected nuclear sites. The U.S. and other Western nations suspect Myanmar has sought and received nuclear advice along with ballistic missile technology from North Korea in violation of U.N. sanctions. A U.S. official said missiles and missile technology are of primary concern but signs of “nascent” nuclear activity are also worrying.

The Obama administration also hopes to loosen Chinese influence in a region where America and its allies are wary of China’s rise. Myanmar has historic ties with China, but has pulled back from a major dam project sought by China amid signs the new leaders are sensitive to criticism that China is taking unfair advantage of its much smaller but resource-rich neighbor.

U.S. officials are cautious about what Clinton’s three-day visit can accomplish beyond being a symbolic stamp of approval for the small steps of political and social reform under way since elections last year. They are careful to point out that there are no immediate plans to lift heavy U.S. sanctions on Myanmar imposed because of an abysmal human rights record.

That could come in time, if Myanmar proves serious about reform. Other steps being contemplated include upgrading diplomatic relations that would see the two countries exchange ambassadors.

Some members of Congress have expressed concern that the trip is an undeserved reward for the regime.

“I am concerned that the visit of the secretary of state sends the wrong signal to the Burmese military thugs,” said Rep. Ileana Ros-Lehtinen, R-Fla., chairwoman of the House Foreign Affairs Committee. “Secretary Clinton’s visit represents a monumental overture to an outlaw regime whose DNA remains fundamentally brutal.”

Suu Kyi said Wednesday that she still supports U.S. sanctions against her country’s government, but will have a better idea of the chances for reform after she meets with Clinton. She said she would like to see cease-fires and serious talks with ethnic minorities fighting the military as well as respect for the rule of law, a clean judiciary and the release of political prisoners.

“There has to be enough progress in those directions for us to be sure the reforms will keep going forward and not regress,” Suu Kyi told a webcast to the Council of Foreign Relations in Washington. “What we have to do is make sure no one can put a stop to the reform process. We all have to cooperate to make sure it goes forward.”

The trip is the first major development in U.S.-Myanmar relations in decades and comes after the Obama administration launched a new effort to prod reforms in 2009 with a package of carrot-and-stick incentives. That effort failed, but rapprochement sped up when Myanmar held elections last year that gave power to a new government that pledged greater openness.

Last week, Myanmar’s parliament approved a law guaranteeing the right to protest, which had not previously existed, and improvements have been made in areas such as media and Internet access and political participation. The NLD, which had boycotted previous flawed elections, is now registered as a party.

But the government that took office in March is still dominated by a military-proxy political party, and Myanmar’s commitment to democratization and its willingness to limit its close ties with China are uncertain.

Corruption runs rampant, hundreds of political prisoners are still jailed and violent ethnic conflicts continue in the country’s north and east. Human rights activists have said Clinton’s visit should be judged on improvements in those conditions.

Myanmar’s army continues to torture and kill civilians in campaigns to stamp out some of the world’s longest-running insurgencies, according to rights groups. They say ongoing atrocities against ethnic minorities serve as a reminder that reforms recently unveiled by the country’s military-backed government to worldwide applause are not benefitting everyone.

Aid groups have reported atrocities that occurred as recently as last month: A village leader was killed, allegedly by soldiers, for helping a rebel group, his eyes gouged out and his 9-year-old son buried beside him in a shallow grave. The boy’s tongue was cut out.