PHNOM PENH, Cambodia – The Obama administration now has a taste of the difficult diplomacy necessary to sharpen the focus of American power on Asia, seeking investment opportunities alongside reforms from rights-abusing governments and working with China while defending U.S. interests.

From democratic Mongolia to once-hostile Vietnam and long-isolated Laos, Secretary of State Hillary Rodham Clinton this week faced governments eager to embrace the United States as a strategic counterweight to China’s expanding military and economic dominance of the region, while still lukewarm about U.S. demands for greater democracy and rule of law.

And after meeting with China’s foreign minister Thursday on her Asia tour, Clinton lauded Washington’s cooperation with Beijing – even as she took up the case of several Southeast Asian nations threatened by the communist government’s expansive claims over the resource-rich South China Sea.

In the discussions across the world’s most populous continent, U.S. officials outlined their belief in greater democracy and freedom for Asian nations. The vision is part of a larger Obama administration effort to redirect U.S. diplomacy and commercial policy to the place most likely to be the center of the global economy over the next century.

It is also a reaction to the region’s slide toward undemocratic China as its economy has boomed and America’s has struggled.

“As we’ve traveled across Asia, I’ve talked about the breadth of American engagement in this region, especially our work to strengthen economic ties and support democracy and human rights,” Clinton said.

“This is all part of advancing our vision of an open, just and sustainable regional order for the Asia-Pacific.”

Clinton today will introduce Myanmar’s reformist president, Thein Sein, to American business leaders looking for investment opportunities.

The U.S. has eased sanctions on the once-reclusive military dictatorship, as the administration seeks to double American exports. Still, Clinton said she would urge Thein Sein to do more.

“Political prisoners remain in detention,” she said. “Ongoing ethnic and sectarian violence continues to undermine progress toward national reconciliation, stability and lasting peace. And fundamental reforms are required to strengthen the rule of law and increase transparency.”