Hillary Rodham Clinton touched down Wednesday in the desolate new capital of Burma, becoming the first U.S. secretary of state to visit the authoritarian country in more than half a century.

She brings with her potential incentives for Burma’s authoritarian leaders to continue their recent movement toward easing political and economic restrictions — and also the intent to press them on the country’s suspected weapons trade with North Korea.

Clinton’s plane was met by a large contingent of Burmese officials, apparently eager to engage with the United States and demonstrate their sincerity about progress after decades of economic sanctions and international criticism over Burma’s crackdown on democratic activists, violence against ethnic minorities and violations of human rights.

“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 shortly before her arrival. “We and many other nations are quite hopeful that these flickers of progress . . . will be ignited into a movement for change.”

Clinton’s visit comes as Burma, also known as Myanmar, appears poised for historic changes — an opening the Obama administration is seeking to encourage through incentives. The arrival of the chief U.S. diplomat is itself the largest reward thus far, lending the reclusive country the international prestige and recognition its leaders crave.

Clinton’s advisers declined to discuss what additional incentives the secretary was bringing on this trip, saying those would depend on her sense in meetings of the government’s willingness to continue reforms.

“We are actually deeply realistic for what can be expected. There have been a number of failed attempts at reform, over decades,” said a senior administration official who was not authorized to be quoted by name. “We are mindful of the risks, and we will be very careful as we go forward.”

The two biggest signs of sincerity that U.S. officials say they are looking for are the release of all political prisoners and an end to the war between government troops and ethnic minorities.

Since October, Burma has released 200 political prisoners. But activists say at least 1,600 remain imprisoned, including some top opposition leaders. Some government officials have blamed the lack of further releases on recent political protests.

“The president has this issue in his mind,” Ko Ko Hlaing, chief political adviser to President Thein Sein, said in an e-mail interview. “I think the next batch of release may be depend upon how the released persons are doing with politics. If their activities are going well in accordance with national reconciliation efforts, I think it will make better condition for next amnesty.”

On ethnic violence, the adviser said, negotiations are taking place. Human rights advocates point out, however, that violent clashes with soldiers occurred as recently as last week.

Clinton will also press the government on its suspected weapons trade with North Korea, officials said. The United States in recent years has blocked North Korean vessels believed to be transporting arms to Burma. And Burmese defectors have accused the junta of illicitly conducting nuclear research.

The senior official traveling with Clinton said the secretary is primarily focused on Burma’s trade in missile technology rather than its nuclear program. “We’ve looked at this fairly carefully, and we do not see signs of a substantial nuclear effort at this time,” he said.

Clinton nevertheless will ask Burmese officials to sign an International Atomic Energy Agency protocol that would open it up to nuclear-related inspections, the official said.

The secretary’s historic visit is partly clouded by uncertainty. Because of Burmese leaders’ habitual secretiveness, U.S. officials acknowledge that they do not know exactly how decisions are made in Thein Sein’s nominally civilian government — nor how much control the president wields.

Thein Sein, like many members of the leadership, is a former military officer. His precise motive for launching the country’s sudden and surprising move toward reform is also unknown, though many suspect it stems in part from a desire to avoid overreliance on China, Burma’s strongest ally but also a voracious consumer of its natural resources.

“China has no resistance toward Myanmar seeking improved relationships with the West, but it will not accept this while seeing its interests stamped on,” the state-run Chinese paper the Global Times said in an editorial about Clinton’s visit.

Clinton will spend Thursday meeting with the president and Burmese parliamentary leaders. Flying next to Rangoon, she will meet, for the first time, Nobel Peace Prize laureate Aung San Suu Kyi, the leader of Burma’s long-persecuted democracy movement.

Speaking via Web video at a Council on Foreign Relations event on Wednesday, Suu Kyi confirmed that she will run for parliament in next year’s elections — another sign of how seriously she is taking the government’s political and economic shifts. She also expressed support for the United States and for Clinton’s moves to engage the government.

Clinton is to have a private dinner with Suu Kyi on Thursday night and meet with her again Friday. She is also scheduled to meet with representatives of Burma’s ethnic minorities and civil service organizations.