Beijing called the reports on Chinese ships transferring oil to Pyongyang unfounded and said the country has always comprehensively and strictly implemented relevant resolutions of the United Nations Security Council and carried out its due international obligations.

Foreign Ministry spokeswoman Hua Chunying made the remarks on Friday after the United States expressed disappointment over Chinese oil exports to the Democratic People's Republic of Korea.

China conducted an investigation immediately, especially regarding a claim that a Chinese ship transferred petroleum products to a DPRK vessel in international waters on Oct 19, and found the report untrue, Hua said at a regular news conference.

She said the ship has never stopped at any Chinese port since August, and there is no record of it entering or leaving a Chinese port, and China is not aware whether it had docked at a port in other countries.

"China will never allow its citizens and enterprises to engage in any activities that violate the UN resolution, and the country will seriously punish any activities that are proven to have violated the relevant resolution in accordance with law and regulations," she said.

UN resolutions on the nuclear issue, including Resolution 2397, have made it clear that the resolutions not only impose sanctions, but also call for peaceful, diplomatic and political solutions and the resumption of the Six-Party Talks, Hua said.

China calls for all parties to implement the UN resolutions "in a comprehensive and balanced manner", and make joint efforts to maintain regional peace and stability, push forward the denuclearization of the Korean Peninsula and solve the issue through dialogue and consultation, she added.

The UN Security Council unanimously adopted a new resolution last week containing tougher sanctions against the DPRK over its continued and advancing nuclear and ballistic missile programs.