China has expressed strong dissatisfaction and lodged stern representations with the United States over a trade agreement signed between the U.S. and China's Taiwan region on Thursday, Chinese Foreign Ministry spokesperson Mao Ning said on Friday.

"China resolutely opposes any form of official exchanges between the Taiwan region and countries that have diplomatic relations with China, including negotiating and signing any sovereign or official agreements," Mao said at a daily briefing.

The U.S. insists on advancing the negotiation of the so-called "U.S.-Taiwan Initiative on 21st Century Trade" with Taiwan's Democratic Progressive Party (DPP) and signing the agreement, which seriously violates the one-China principle, the three China-U.S. joint communiques, and the commitment made by the U.S. to maintain only unofficial relations with Taiwan, Mao said, adding that China strongly opposes such an act.

The "initiative" is nothing but another example for the U.S. to hollow out the one-China principle, she said.

Mao said China again urges the U.S. to abide by the one-China principle and the three China-U.S. joint communiques, immediately stop any official exchanges with Taiwan in any form, withdraw the "initiative" and stop sending any wrong signals to "Taiwan independence" separatist forces.

The Taiwan Affairs Office of the State Council Friday also responded to the issue, saying that the DPP has traded the interests of Taiwan's enterprises and people for progress in its relations with the U.S. 

"We resolutely oppose the negotiation and signing of any agreement that has a sovereign implication or is official in nature between the United States and the Taiwan region," said Zhu Fenglian, spokesperson for the Taiwan Affairs Office of the State Council. 

The DPP authority's act went against the will of the people and will harm itself and the Taiwan region, she added.