China's Foreign Ministry Spokesperson Zhao Lijian’s remarks in full here

https://www.fmprc.gov.cn/mfa_eng/xwfw_665399/s2510_665401/202208/t20220801_10731629.html

Here are some of his remarks - in full below:

China has serious concern & firm opposition over Speaker Pelosi’s potential visit to Taiwan 

(the visit would) lead to a very serious situation and grave consequences.

Those who play with fire will perish by it.

such a visit would lead to serious consequences

the Chinese side is fully prepared for any eventuality and the People’s Liberation Army of China will never sit idly by

(The US must) not arrange for a visit by Speaker Pelosi to Taiwan. 

NPR: Two questions about Nancy Pelosi’s visit to Asia. The first is that in her official schedule, she said she’s going to Singapore, Malaysia, South Korea and Japan. There was obviously no mention of Taiwan. What’s China’s take on that? Is that cause for optimism? The second question is, you said the military would not sit by idly. Can you elaborate on that? What are we likely to see if she were to visit Taiwan? 

Zhao Lijian: On your first question, we’ve seen the press release issued by Speaker Pelosi’s office, her own tweets and the press reports. I have made the Chinese government’s position very clear just now. 

On your second question, Pelosi is the third highest-ranking official in the US government, which means it would be highly sensitive for her to visit Taiwan no matter what. Whatever the timing or way she chooses to go to Taiwan, it will seriously violate the one-China principle and the provisions of the three Sino-US joint communiqués and seriously undermine China-US relations. It will undoubtedly create an egregious political impact. If Pelosi visits Taiwan, the Chinese side will respond resolutely and take strong countermeasures to defend our sovereignty and territorial integrity. As for what those measures will be, let's see what happens if she actually goes.

Phoenix TV: John Kirby, National Security Council Coordinator for Strategic Communications at the White House, said that the US has seen no evidence of looming Chinese military activity against Taiwan. “If such a visit occurred, it would signal no change in US policy”, he said, adding that there is no reason for the US and China to “come to blows” or to “come to increased physical tension”. Do you have any response?

Zhao Lijian: The Chinese side has repeatedly made clear our serious concern over Speaker Pelosi’s potential visit to Taiwan and our firm opposition to the visit. We will take firm and strong measures to safeguard our sovereignty and territorial integrity. I would like to stress that the one-China principle is what underpins peace and stability across the Taiwan Strait. It is the US side that has kept distorting and hollowing out the one-China policy, making irresponsible remarks and creating factors of tension on the Taiwan question. The US has recently begun to emphasize the importance of upholding all countries’ sovereignty and territorial integrity. We hope the US will honor those words first and foremost on the Taiwan question and refrain from applying double standards.