The US Deputy Secretary of State kicked off a visit to China on Wednesday to mark 30 years of diplomatic ties between the two nations and give the Bush administration's farewell to the Chinese leadership.
John Negroponte was due to meet with China's Vice President XI Jinping and Foreign Minister Yang Jiechi during his visit, when he was also expected to discuss issues such as North Korea's nuclear programme and the economic crisis.
"North Korea, Iran... It's a broad relationship. I'm sure they'll talk about economics as well," US State Department spokesman Sean McCormack said late on Tuesday.
But Negroponte's visit was first and foremost aimed at celebrating the 30th anniversary of diplomatic ties between the two countries, he said.
"The primary reason for the visit is to commemorate that 30th anniversary," McCormack said.
US Secretary of State Condoleezza Rice had been due to attend the commemorative events in her last trip abroad before the end of US President George W Bush's reign and Barack Obama's move into the White House on January 20.
But she was forced to cancel to focus on the Middle East conflict, and she sent Negroponte instead.
The two countries established formal ties on January 1, 1979, when the United States switched its diplomatic recognition to communist-ruled China, ending decades of support for the Nationalist Chinese government of Taiwan.
The Nationalists had fled to Taiwan from mainland China in 1949 after losing a civil war.
Negroponte was due to attend a friendly table tennis match on Wednesday to commemorate so-called 'ping-pong diplomacy', a term that refers to China inviting the US table tennis team to tour the country in 1971.
The event kick-started a period of warming relations between the two countries that eventually led to the establishment of formal ties.
Negroponte was due to meet Yang after the ping-pong match on Wednesday, and was to hold talks with Xi on Thursday before heading back to the United States.
Liu Weidong, a researcher at the Chinese Academy of Social Science, the top government think-tank, said there had been a lot of progress in relations between the two countries in the past 30 years, but problems remained.
"There's a lack of strategic mutual trust between the two sides... They have different values," he said.
"The US was worried about whether China's rise was peaceful, and now it is worried about whether China can remain peaceful after it rises," he said.
However, publicly at least, China's top leadership has spoken warmly in recent days of the nation's relations with the United States.
"In a new historical period, China and the United States will definitely be able to stick firmly to the overall direction of a relationship characterised by constructive cooperation," Chinese President Hu Jintao told Bush in a phone call.
David Zweig, an expert on China foreign relations at the Hong Kong University of Science and Technology, said the relationship between the two nations was becoming increasingly important for world affairs.
"The way power is distributed now in the world is you've got one dominant power -- the US -- and another power that is rising -- China," Zweig said.
"How those two powers deal with each other will determine a lot about the future of the world over the next 30 years."