"They must seize this golden opportunity to help save Chen and his family and demonstrate to the world that the (United States) stands firm for fundamental human rights and the rule of law," said Smith, the chairman of the Congressional-Executive Commission on China. "Trade talks are important, but human rights are not 'an irritant' -- we have a duty to protect and defend."

Later Thursday, Smith chaired an emergency hearing on the issue that included a telephone conversation with Chen from Beijing amplified by holding a cellular phone up to a hearing room microphone.

Speaking to Chen, Smith called his case a test of the Chinese government's commitment to protect him and "also a test of the United States as to whether or not human rights really do matter."

Carney, repeatedly asked about the issue by reporters at the White House daily briefing, said the president is "not concerned about political back-and-forth on this issue."

"He is focused on the need to advance U.S. interests in our relationship with China" and to make "an open and frank discussion on human rights" part of that relationship, Carney said.

Human rights advocacy groups raised doubts about whether Beijing would stick to the promises it reportedly made regarding Chen's ability to live free of persecution in China.

Chinese officials did not comment directly on what deal had been reached with the United States over Chen. In comments reported by state media, they focused on what they described as "interference" by Washington in China's internal affairs.

To Kenneth Lieberthal, director of the John L. Thornton China Center and a senior fellow in foreign policy at the Brookings Institution, the balance of human rights issues such as the Chen case with other significant issues for both the United States and China marked a maturing of relations between the countries.

"The juxtaposition of a classic human rights issue with these other issues highlights the range of our relationship and our capacity now to do what U.S. policy has sought -- which is to deal with these issues separately so that problems in any one part of the relationship don't disrupt our ability to address very important issues in other parts of the relationship," Lieberthal said on the Brookings website. "That's what a mature relationship is about."

A co-author of a book on Obama's foreign policy published in March, Lieberthal said the balanced approach by Washington "does not mean, as some in the advocacy community have said, that this means that effectively we don't give much priority to human rights."

"What it does mean is that we give priority to human rights, we give priority to nuclear proliferation, we give priority to cybersecurity, we give priority to jobs and economic growth in the United States and how China's economic polices affect that," said Lieberthal, a former University of Michigan professor who was a special adviser on national security affairs to President Bill Clinton. "We have a series of priorities, each of which we pursue vigorously, and I think that's the right way to do it."

Carney seemed to agree Thursday, telling reporters: "We are continuing to pursue our broad agenda with China on a whole range of issues."