Taiwan is an inalienable part of China's territory, and the one-China principle is the prerequisite for Taiwan to participate in foreign economic cooperation, a spokesperson of the Ministry of Commerce said Tuesday.

The comments came after the United States announced that it would sign the first agreement with the Taiwan region of China under the "U.S.-Taiwan Initiative on 21st Century Trade."

China always firmly opposes countries that have diplomatic relations with it to conduct any form of official exchanges with Taiwan, including the negotiation and signing of any economic and trade agreement with sovereignty implications and official nature, said the spokesperson.

The spokesperson urged the United States to adhere to the one-China principle and the provisions of the three China-U.S. joint communiques, fulfill its commitment of not supporting "Taiwan independence," and carefully handle economic and trade relations with Taiwan.