Aug. 10 (UPI) -- Chinese fighter jets trespassed the center of the Taiwan Strait in an apparent warning to Taipei as Taiwan received its highest-level U.S. official visit since 1979.
Chinese fighter jets Shenyang J-11 and Chengdu J-10 crossed the unofficial boundary that separates Taiwan from the mainland on Monday, Taipei's ministry of national defense said, according to Taiwan News.
The "People's Liberation Army Air Force jets' deliberate intrusion...in the Taiwan Strait have seriously undermined regional security and stability," Taiwan's air force said following the incident.
Taiwan also said that it could "respond appropriately to changes in the enemy's disposition to maintain the security of the homeland," according to the report.
Reports of trespassing Chinese fighter jets came the same day U.S. Secretary of Health and Human Services Alex Azar and his Taiwanese counterpart Chen Shih-chung witnessed the signing of a memorandum of understanding on health cooperation.
Chen said the agreement implies greater cooperation between the two sides on global health security.
"Through these concrete actions, we hope to improve the health and well-being of the people of Taiwan and the United States and also promote global health security in the Indo-Pacific region, as well as across the world," Chen said, according to Taipei Times on Monday.
The agreement would allow the two governments to collaborate on next-generation COVID-19 tests and work together on a vaccine in what could be more than a $2 billion program, the report says. Taiwan has been praised as a COVID-19 success.
Azar's visit drew harsh rebuke from China, which has opposed Taiwan's entry into the World Health Organization. China does not recognize Taiwanese sovereignty.
Beijing foreign ministry spokesman Zhao Lijian said Monday in response to Azar's visit China opposes government-level exchange between the United States and Taiwan.
Taiwan is the most important issue in U.S.-China relations, Zhao said.