SIEM REAP, Cambodia — Secretary of State Hillary Rodham Clinton declared Myanmar open to American investment Friday, introducing the reformist president to leaders of some of the biggest US corporations and prodding him to do more to expand democracy in his long-reclusive country.
Following the Obama administration’s recent loosening of sanctions against Myanmar, Clinton met President Thein Sein for an hour in the Cambodian city of Siem Reap, praising him for several prodemocracy reforms.
Clinton and Thein Sein shared a warm greeting in a hotel courtyard, their national flags and tropical foliage behind them.
The two seemed much more personally engaged than when they met last year, when Clinton became the first US secretary of state in half-a-century to visit Myanmar. The city hosts the famous centuries-old temples of Angkor, recalling an earlier age of regional glory.
‘‘I brought a very prestigious business delegation to see you. I wanted them all to hear from you tonight about your plans for the future,’’ Clinton told Thein Sein, and she also asked after his family.
They then met the largest delegation of American businesses to Southeast Asia, including Coca Cola, Ford Motor Co., General Electric, General Motors, Goldman Sachs, and Google.
Clinton called this week a ‘‘milestone’’ in US-Myanmar relations as the Obama administration lifted restrictions on investments in the country. She said US officials were taking 70 company representatives to Myanmar this weekend to speak with officials and explore opportunities.
‘‘We’re excited by what lies ahead and we’re very supportive of President Thein Sein’s economic and political reforms,’’ she said.
The high-profile meetings reflected the sharp progress the country, also known as Burma, has made after years in the international wilderness.
Western economic and political sanctions had been imposed on Myanmar’s previous military regime for its repressive and undemocratic policies. Thein Sein, who took power last year after a general election, has instituted liberalizing reforms in an effort to ease the sanctions and attract foreign aid and investment.
Thein Sein’s government has enlisted Nobel laureate Aung San Suu Kyi in its political reconciliation efforts, welcoming her party into Parliament after more than two decades of hostility that included 15 years for the dissident under house arrest.
‘‘We want to help you keep going. We’re very committed,’’ Clinton told Thein Sein ahead of their bilateral meeting.
‘‘I am very pleased to see our bilateral relationship improving dramatically . . . We are pleased that President Obama eased the sanctions,’’ said the Myanmar leader.
In their talk, Thein Sein told Clinton he would manage his country’s expected new wealth responsibly, sharing it among its people, said a US official who was present at their meeting and who spoke on condition of anonymity because of its private nature.
Although the spotlight was on business, Clinton also pressed Thein Sein on human rights issues, said the official, specifically raising the fate of a Muslim ethnic group in western Myanmar.
The Rohingyas have been the target of discrimination, and tensions with Rakhine Buddhists last month exploded into violence that left at least 78 people dead and tens of thousands homeless.
Clinton stressed that the United States considers the Rohingya ‘‘internally displaced persons.’’ Thein Sein this past week had proposed that the UN High Commissioner for Refugees resettle the Rohingya in a third country or take responsibility for them, a suggestion rejected by the United Nations as unsuitable.
Thein Sein’s response to Clinton on the issue was to describe the situation as ‘‘very dangerous,’’ said the official.