China has notified its local governments on how to implement new U.N. sanctions on North Korea, including specific measures on imports from North Korea, a diplomatic source with knowledge of the matter said Monday.

Kim Hong-kyun, South Korea's chief nuclear envoy, held talks with his Chinese counterpart, Wu Dawei, last Friday as the two nations vowed to fully implement the new U.N. sanctions against North Korea's fourth nuclear test and rocket launch.

During the talks, Wu told Kim that China has been "in the process of implementing the new U.N. resolution on North Korea," said the source, who attended the Friday meeting.

"The Chinese side also believes that strong sanctions are needed to show its sincerity on denuclearization," the source said.

Earlier this month, the U.N. Security Council levied tougher sanctions against North Korea's fourth nuclear test on Jan. 6 and the Feb. 7 launch of a long-range rocket, both of which violated previous U.N. resolutions.

The new U.N. sanctions require countries to limit or ban imports of North Korean coal, iron ore and other mineral resources if the proceeds are used for the North's nuclear and missile programs.

One of the potential loopholes is a provision that allows North Korea to continue exports of coal and iron ore if such transactions are for "livelihood purposes."

North Korea has remained defiant of U.N. resolutions, threatening to launch a nuclear strike on South Korea and the U.S.

as well as conduct another nuclear warhead test and more ballistic missile launches.

After talks with Wu, Kim told reporters that China is open to holding three-way talks with South Korea and the United States on implementing the new U.N. sanctions.

The source said China showed its "sincerity" about the three-way talks with South Korea and the U.S., but the specific date of the proposed talks has not been set.

China's proposal of pursuing peace treaty talks with North Korea in tandem with denuclearization was one of the topics of the talks between Kim and Wu.

The aim of the Chinese proposal is to help North Korea "come to the negotiating table," said the source, citing remarks from Chinese officials during the Friday talks. (Yonhap)