A Chinese defense spokesperson on Thursday said the Chinese People's Liberation Army (PLA) will resolutely safeguard the country's national sovereignty and territorial integrity, and will leave no room for "Taiwan independence" separatist activities in any form.

Tan Kefei, a spokesperson for China's defense ministry, made the remarks in response to a press inquiry on recent provocative acts by the United States, which have heightened tensions in the Taiwan Strait.

The root cause of increasing tensions in the Strait is the Democratic Progressive Party authorities' provocative acts to collude with external forces in seeking "Taiwan independence," and their obstinate determination to stand on the opposite side of the Chinese nation's fundamental interests, Tan said.

It is justified for the PLA to carry out military operations in response to external interference and secessionist activities seeking "Taiwan independence," Tan added.

Taiwan is China's Taiwan, and the Taiwan question is purely China's internal affair and the core of China's core interests, Tan said, stressing that the Taiwan question is the first red line that can not be crossed in China-U.S. relations.

China firmly opposes any form of official exchanges or military contact between the United States and Taiwan, and resolutely opposes the United States elevating its substantive relations with Taiwan in any form, Tan said.

"We urge the United States to give up its attempt to use Taiwan to contain China, and cease its 'salami tactics' and further action on the Taiwan question," Tan said.