BALI, Indonesia — Secretary of State Hillary Clinton will visit Burma next month, a White House official said Friday, in a thawing of diplomatic ties between the United States and the Southeast Asian nation whose strong-arm government has outraged the West.

It would mark the first visit by a U.S. secretary of state in 50 years.

The announcement was made as President Obama began a series of meetings with Southeast Asian leaders and was to participate in a meeting of the Association of Southeast Asian Nations, whose chairmanship recently went to Burma, also known as Myanmar.

Burma’s military rulers have taken a hard anti-democratic line, cracking down on opposition leaders including Nobel Peace Prize laureate Aung San Suu Kyi, who had been on house arrest for years. But she was freed last year, and hundreds of other political prisoners have been set free since in a sign that Burma might be signaling an opening to the West as a hedge in its relationship with China.

A senior Obama administration official said the president called Suu Kyi Thursday night from Air Force One as he flew into Bali.

In brief remarks here in Bali on Friday, Obama said: “We remain concerned about Burma’s closed political system, its treatment of minorities and holding of political prisoners, and its relationship with North Korea. But we want to seize what could be an historic opportunity for progress, and make it clear that if Burma continues to travel down the road of democratic reform, it can forge a new relationship with the United States of America.”

On her trip, Secretary Clinton will press Burma to pursue more reforms, Obama said.

Obama also mentioned Burma during his speech to Australia’s parliament Thursday before heading to Bali.

“The government has begun a dialogue,” Obama said. “Still, violations of human rights persist. So we will continue to speak clearly about the steps that must be taken for the government of Burma to have a better relationship with the United States.”