A top Chinese official and US Secretary of State Hillary Clinton held "frank and in-depth" talks on Syria by telephone Monday as Chinese Vice President Xi Jinping began a visit to the United States.

China and Russia have faced a barrage of international criticism this month for blocking a UN Security Council resolution condemning the bloody crackdown on protesters in the Middle East country.

State Councillor Dai Bingguo and Clinton -- a fierce critic of China's veto decision -- had "a frank and in-depth exchange of views on the current Syria situation", the official Xinhua news agency said Tuesday.

Dai told Clinton that the violence was "essentially Syria's internal affair" and China backed efforts by the Arab League to resolve the conflict through political means, Xinhua said.

He added that China's position on Syria had been "objective and fair and its attitude was responsible", the report said.

Clinton, who has described the UN Security Council veto as a "travesty" and accused China and Russia of "protecting the brutal regime" in Damascus, said the United States would continue to discuss Syria with China.

The phone call came as Chinese Vice President Xi Jinping, the country's leader-in-waiting, arrived in the United States for talks with President Barack Obama and other top leaders including Vice President Joe Biden.

Since the controversial veto, China has held talks with the National Coordination Body for Democratic Change (NCB) -- one of the main opposition factions in Syria -- in Beijing.

The group opposes foreign military intervention in the Syrian conflict -- in line with China's long-standing policy of non-interference in other nations' internal affairs.

Beijing has also said it is considering sending envoys to the Middle East to help resolve the conflict, after Russia sent its top diplomat Sergei Lavrov to Damascus.