A senior U.S. State Department official says China's likely next president Xi Jinping has cancelled a meeting with visiting Secretary of State Hillary Clinton.

The official says Xi's meeting was called off “for unexpected scheduling reasons,” adding that his meetings with the Singaporean prime minister and a Russian official were also cancelled on Wednesday.

Clinton met earlier Wednesday with China's current President Hu Jintao and other senior officials in Beijing, for talks expected to be dominated by China's escalating territorial disputes in the South China Sea.

After arriving in the Chinese capital late Tuesday, Clinton met her Chinese counterpart Yang Jiechi and said Washington is “committed to building a cooperative partnership with China.” She also said the U.S.-China relationship is a key part of the Obama administration's policy of boosting U.S. engagement in the Asia-Pacific region.

Clinton wants Beijing to work with the Association of Southeast Asian Nations, or ASEAN, on a code of conduct for preventing territorial disputes from escalating in the resource-rich South China Sea.

China claims almost the entire sea and opposes entering into multi-lateral negotiations that would give smaller ASEAN members greater clout. Beijing prefers bi-lateral negotiations that would give it more leverage over rival claimants such as Brunei, Malaysia, the Philippines, Taiwan and Vietnam.

Earlier, Clinton was in the Indonesian capital Jakarta, where she urged Southeast Asian nations to reach agreement on dealing with China as a unified bloc. She made the appeal in meetings with Indonesian President Susilo Bambang Yudhoyono and ASEAN Secretary-General Surin Pitsuwan.

Wednesday, Clinton is to meet more Chinese officials, including President Hu Jintao, Vice President Xi Jinping and State Councilor Dai Bingguo.

Before those talks, Chinese Foreign Ministry spokesman Hong Lei warned against U.S. “interference” in the region's maritime disputes.

“We have noticed the United States has said many times that it will not hold a position on the South China Sea issue. We hope they can keep their promises and do more things that are conducive to regional peace and stability, not the opposite.”

Chinese state media also published a series of articles criticizing U.S. policy in the Asia-Pacific on Tuesday. Communist party newspaper The Global Times accused Secretary Clinton of causing “profound mutual distrust” between Beijing and Washington and said “many Chinese people dislike” her. The Xinhua news agency labeled the United States a “sneaky trouble-maker.”

Ralph Cossa, a security analyst at the Hawaii-based Pacific Forum, told VOA there is little chance of an all-out armed conflict between China and any of its rival claimants. But, he also said Clinton is unlikely to make any substantial progress on a code of conduct during her China visit.

“I am very pessimistic that a meaningful code of conduct will be established. There may at some point be something that's called a 'code,' but I doubt that it will have any verification or enforcement mechanisms. And, without that, it will be just another piece of paper that people will violate.”

Washington has said it does not take sides in the sea disputes, but has been critical about China's increasingly assertive maritime claims. On Monday, Clinton did not criticize China directly, but said “no party should take any steps that would increase tensions or do anything that would be viewed as coercive or intimidating.”

Clinton is in the middle of a six-nation Asian tour, her third to the region since May, as she helps implement Washington's strategic “pivot” toward the Pacific. It could be her last visit to China as secretary of state, as she has pledged to step down at the end of President Obama first term in office.

The top U.S. diplomat's talks in China also were expected to focus on human rights, as well as several other international issues, including the Syrian crisis and the Iranian nuclear program. Her last visit to China was overshadowed by the plight of Chinese dissident lawyer Chen Guangcheng, who took refuge in the U.S. embassy and later fled to the United States after reporting abuses while under house arrest in China.