Chief US nuclear negotiator Christopher Hill met his Chinese counterpart Wu Dawei in Beijing on Wednesday.

After discussing the stalled six party talks, the US Assistant Secretary of State told reporters the talks are at a difficult phase.

"I think it's, clearly, we're in a very different moment for the six party process because the DPRK is not giving any signals that it wants to return."

Hill has also acknowledged China's efforts to prompt North Korea to return to the six-party talks, saying the US will not urge China to pressurize North Korea.

"What happened in July was a very difficult time for China. I know China worked very hard to put together various drafts. That's a lot of work for Chinese. I'm sure many of us appreciate the work."

Christopher Hill is expected to travel to other cities including Chengdu, Guangzhou and Shanghai, before continuing to South Korea.

Meanwhile, Chinese Foreign Ministry spokesman Qin Gang says China still considers the six-party talks an effective mechanism for resolving the nuclear issue on the Korean Peninsula.

He adds China will keep in close contact with other parties, work together to strive for early resumption of the talks, and the final goal of a nuclear-free Korean Peninsula.