The Chinese Foreign Ministry on Friday voiced firm opposition to several U.S. lawmakers' visit to China's Taiwan region.

It is reported that six U.S. lawmakers, including Democrat Senator Bob Menendez, chairman of the U.S. Senate Foreign Relations Committee, and Republican Senator Lindsey Graham landed in Taiwan on Thursday and will meet with Tsai Ing-wen.

"U.S. lawmakers should follow the one-China policy that the U.S. government adheres to, abide by the one-China principle and the three Sino-U.S. joint communiques, and stop official exchanges between the U.S. and Taiwan. They should not make irresponsible comments. China will continue to take resolute measures and firmly defend our national sovereignty and territorial integrity," spokesperson Zhao Lijian said at a regular press conference.