A top Chinese official has warned of a "trust deficit" between Beijing and Washington and expressed hopes that a key visit to the United States next week by China's leader-in-waiting will strengthen ties.

Vice Foreign Minister Cui Tiankai made the remarks in a speech published on the ministry's website on Tuesday, as Beijing and Washington lock horns over China's decision to veto a UN resolution on the bloody violence in Syria.

"There is indeed a trust deficit between China and the United States," Cui said in a speech on Monday but only published on the foreign ministry website Tuesday.

"Each time the Sino-US relationship has problems, there are voices that fundamentally doubt the relationship.

"Nurturing and deepening mutual trust remains a major issue that both sides must give full attention to and seriously address."

China's Vice President Xi Jinping will travel to the United States on Monday on a visit seen as part of efforts by the administration of US President Barack Obama to court the leader-in-waiting, about whom little is known in Washington.

His trip comes after US Secretary of State Hillary Clinton strongly criticised China's veto of a UN Security Council resolution condemning Syria for its violent crackdown on protests, calling the move a "travesty".

There are also concerns in Washington about Beijing's rising military spending, while many Chinese policymakers are convinced that Washington is trying to contain the Asian power.

Cui said Xi, who is likely to succeed President Hu Jintao in a major leadership transition that begins this year, could help improve trust between the world's two biggest economies.

"We hope both sides can seize the opportunity of this visit to strengthen communication, enhance mutual trust, expand cooperation, deepen friendship, and push forward the Sino-US partnership," he said in a speech delivered Monday in Shanghai.

Foreign ministry spokesman Liu Weimin, however, played down Cui's comments on Tuesday, telling reporters that differences between China and the United States were "quite normal".

Xi will meet with President Barack Obama on February 14 and is expected to deliver a speech in Washington before heading to Iowa.