China has condemned the United States for interfering in Taiwan affairs and urged it to stop official and military exchanges with the region.

"China firmly opposes any form of official interaction between the U.S. and Taiwan authorities, as well as U.S. interference in Taiwan affairs in any form or under any pretext," Foreign Ministry spokeswoman Mao Ning said on Thursday at a regular news conference.

Mao made the remarks after Mike Gallagher, a member of a delegation of U.S. lawmakers visiting the region, reportedly said that "support for Taiwan will continue regardless of who occupies the White House".

Reiterating that Taiwan is an inalienable part of China's territory, the spokeswoman called on the U.S. to fully understand the "extreme complexity and sensitivity" of the Taiwan question.

The U.S. should abide by the one-China principle and the three China-U.S. joint communiques, handle Taiwan-related issues prudently and properly, and stop sending any wrong signals to "Taiwan independence" separatist forces, she said.

Mao also slammed the U.S. for its military deals with Taiwan, after the Pentagon's Defense Security Cooperation Agency announced on Wednesday that the U.S. State Department has approved the potential sale of "advanced tactical data link system upgrade planning" worth about $75 million to the region.

The U.S. move is a serious violation of the one-China principle and the three China-U.S. joint communiques, especially the one issued on Aug 17, 1982, she said. It also undermines China's sovereignty and security interests, China-U.S. ties and peace and stability across the Taiwan Strait, she added.

Mao urged the U.S. to stop selling arms to Taiwan, and stop creating factors that could cause tensions across the Strait. "China will take strong and resolute measures to firmly defend its sovereignty and territorial integrity," she said.