China started military operations surrounding Taiwan on Wednesday, days after US President Joe Biden declared the US would intervene militarily if Beijing attempted a forcible reunification with the island.

Despite decades of separate rule, China continues to see Taiwan as its territory. If necessary, Chinese President Xi Jinping has threatened to take the island. “The People’s Liberation Army’s (PLA) recent patrol and training activities near Taiwan Island were required actions against Taiwan’s and the United States’ cooperation,” a Chinese defense spokesperson was cited as saying by Xinhua on Wednesday.

The PLA Eastern Theater Command recently staged a joint war-preparedness alert patrol and combat training exercises involving troops from several services and arms in the oceans and skies around Taiwan Island, according to Tan Kefei, a spokesperson for the Ministry of National Defense.

“These are appropriate actions taken in response to the collusion between Taiwan and the US, and in accordance with the necessity to protect national sovereignty and territorial integrity,” Tan added.

Tan claimed that pursuing “Taiwan independence” is doomed to fail, as is supporting such actions, and that the US is jeopardizing the situation by using the “Taiwan card” to limit China.

He stated that the PLA is on high alert and prepared to take all necessary measures to counter any external intervention and secessionist moves for “Taiwan independence.”

China’s harsh reaction comes after US Vice President Joe Biden declared on Monday that the US is prepared to intervene militarily to defend Taiwan in the event of an invasion.

On Monday, Biden met with Japanese Prime Minister Fumio Kishida to discuss bilateral, regional, and global collaboration.

Biden emphasized Washington’s commitment to safeguarding the security of the Taiwan Strait and opposing unilateral changes to the status quo during a joint press conference with Japanese Prime Minister Shinzo Abe.

When asked if the US is prepared to intervene militarily in Taiwan’s defense, he said yes, adding that this is the pledge that the US has made.

“We will continue to work for peace and stability in the Taiwan Strait. The United States remains firm with Japan and other nations in opposing China’s takeover of Taiwan “he stated.