Chinese President Hu Jintao's latest state visit to the United States was "very important" and "made progress" on enhancing China-U.S. relations, a U.S. international affairs expert said Friday.

Kenneth Lieberthal, director of the John L. Thornton China Center and senior fellow at the Brookings Institution, told Xinhua in an interview that in his view, the fundamental major achievement of Hu's visit was that both sides had approached the situation, to use an American term, as an "eyes wide open" relationship.

Lieberthal added that the Chinese and U.S. presidents made very clear that the China-U.S. relationship "is too important for us to allow it to deteriorate."

Hu's visit "made progress on those issues and that those issues are ones that always need constant work," Lieberthal said.

He added that the visit "was very important for both sides to have realistic, pragmatic, stable expectations of the other" and "to understand not only what are the problems in the relationship but also to understand how those problems look from the other side."

"We have too many overlapping interests and goals that are of significance bilaterally, regionally and globally," Lieberthal said.

He said both President Hu and President Barack Obama made very clear that China and the United States were fully aware of where they differ. Some of those differences stem from different cultures and histories, and some from national interests.

"I think both are committed to working to prevent those differences from seriously reducing our ability to pursue the very important areas where we have similar interest and goals, which are the major part of the relationship," Lieberthal said.

In the American view, he said, "China has taken a helpful step in a constructive direction" with regards to the Korean Peninsula nuclear issue.

China has also made important and constructive moves with regard to the Iranian nuclear issue and played a constructive role in the Sudan referendum, Lieberthal added.

"So in a variety of ways on the security agenda, and also on the economic and trade agenda, we've seen some things move forward," he said.

Lieberthal said he also thought that Hu's visit produced a lot in terms of specifics as well as in the very important area of framing the Sino-U.S. relationship in a reasonably sound fashion.

The expert acknowledged that last year was a difficult year for the China-U.S. relationship. But Hu's visit "puts us on a solid footing moving forward and therefore played a very useful role."

During President Hu's state visit to the United States from Tuesday to Friday, the two sides agreed to build a China-U.S. cooperative partnership based on mutual respect and mutual benefit.