U.S. Assistant Secretary of State for East Asian and Pacific Affairs Kurt Campbell discussed the North Korean nuclear issue with Chinese officials on Tuesday.

The U.S. and China have not disclosed what Campbell discussed in Beijing but diplomatic sources in the Chinese capital speculate the U.S. official could have been briefed on North Korean leader Kim Jong-il's recent trip to China. Sources also believe Campbell may have discussed steps to resume the six-party nuclear dialogue.

Campbell also could have met with China's top nuclear envoy Wu Dawei or Wang Jiarui, chief of the Chinese Communist Party's International Liaison Department.

Campbell is scheduled to visit Seoul on Friday.