A U.S. delegation headed by Christopher Hill, assistant secretary of state for East Asian and Pacific affairs and the top U.S. negotiator on the Korean Peninsula nuclear issue, arrived in Beijing Sunday afternoon for the second phase of the fifth-round six-party talks.

"I'm here to do more progress on the September, 2005 agreement," Hill told reporters at the Beijing Capital International Airport.

"The DPRK (the Democratic People's Republic of Korea) needs to get serious about the denuclearization issue," the U.S. chief negotiator said, adding "a lot of good things" could happen if the DPRK gets serious about the denuclearization issue.

He warned that nothing could achieve if the DPRK delegation is not serious about denuclearization.

Five of all the six parties involved in the talks have gathered in the Chinese capital to attend the upcoming talks scheduled to start in Beijing on Dec. 18.