A senior South Korean official is in China this week in an effort to restart multi-party talks on North Korea's nuclear weapons program.
During his four-day visit, the South Korean Unification Minister will meet with top Chinese officials in Beijing, including Chinese Foreign Minister Li Zhaoxing.
Chung Dong-young is visiting as South Korean President Roh Moo-hyun's special envoy.
On his arrival Tuesday, Mr. Chung told reporters the efforts to resolve the nuclear standoff with Pyongyang are entering a critical period.
Mr. Chung said both Seoul and Beijing hope to solve the North Korean nuclear problem peacefully.
Foreign Ministry spokesman Liu Jianchao said the two countries are working closely on the disarmament issue.
"The most important thing is for the relevant parties to show more flexibility in order to restart the talks as quickly as possible," he said.
South Korea, China, Japan, Russia and the United States have met three times with North Korea to try persuading it to give up its nuclear arms programs.
The talks have produced no significant gains and North Korea has thus far not agreed to attend a fourth round.
Pyongyang says the United States must drop what it considers a hostile policy before new talks can begin. The United States, however, insists that North Korea must comply with several commitments it has made to be free of nuclear arms.