The statement was made during Biden's meeting with China's leader-in-waiting, Xi Jinping during his visit to the south-east Asian country.
Speaking in the Great Hall of the People, in central Beijing, Biden told Xi, "I would suggest that there is no more important relationship that we need to establish on the part of the United States than a close relationship with China."
And added, "I am absolutely confident that the economic stability of the world rests in no small part on cooperation between the United States and China."
Xi responded back by saying, "I too believe that under the new conditions, China and the United States have ever more extensive common interests and we shoulder ever more important responsibilities."
And added, "We would like to work with your country to promote the development of relations between our two great nations."
Ever since the credit rating agency - Standard & Poor's - downgraded US to AA+ from AAA, the Chinese state media have been blaming Washington's reckless fiscal policies for the current mess. They have expressed concerns about Beijing's big holdings of dollar assets.
Analysts say that China wants Biden to assure it, that its vast holdings of dollar assets and US Treasury debt remain safe and unaffected by the credit rating downgrade.