No country, organization or individual should imagine that they can step on or even cross China's red line on the Taiwan question without paying a price, a spokesperson for the Chinese Foreign Ministry said on Monday.

In response to a query about China's decision to take countermeasures against U.S. military contractors and senior executives involved in arms sales to China's Taiwan region, spokesperson Lin Jian told a press briefing that such sales seriously violate the one-China principle and the stipulations of the three China-U.S. joint communiques, particularly the August 17 Communique of 1982, and undermine China's sovereignty and territorial integrity.

China has implemented legal countermeasures against the main contractors and senior executives involved in recent U.S. arms sales to Taiwan. These measures also target military-industrial enterprises that have participated in arms sales and attended the "U.S.-Taiwan Defense Industry Conference" in recent years, according to the spokesperson.

Lin stressed that the Taiwan question is at the heart of China's core interests and is the most important red line that cannot be crossed in China-U.S. relations.

"No one should underestimate the strong determination, will, and ability of the Chinese government and people in defending national sovereignty and territorial integrity, or imagine that they can step on or even cross the line on the Taiwan question without paying a price," he added.