BEIJING, Jan. 13 (Xinhua) -- A Chinese mainland official Wednesday reaffirmed the mainland's firm opposition to arms sales to Taiwan by any country and called on Taiwan to cherish hard-won peaceful development of cross-Strait relations.

Yang Yi, spokesman of the State Council Taiwan Affairs Office, made the remarks here when asked to comment on reports of U.S. arms sales to Taiwan.

He called on Taiwan to do more things to promote the peaceful development of cross-Strait relations.

China's ministries of foreign affairs and national defense had expressed firm opposition to the U.S. arms sales to Taiwan amid reports that the U.S. Defense Department had recently awarded Lockheed Martin Corp a contract for selling an unspecified number of advanced Patriot missiles to Taiwan.

Foreign Ministry spokeswoman Jiang Yu on Saturday urged the U.S. to "clearly recognize the severe consequences of arms sales to Taiwan, reject the cold war mentality, and adhere to the three Sino-U.S. joint communiques, especially the principles established in the Joint Communique on Aug. 17, 1982."

The "Aug. 17 communique" stated that the U.S. would not seek to carry out a long-term policy of arms sales to Taiwan, and intended to gradually reduce arms sales.