China responded to the McCarthy meeting by imposing a travel ban and financial sanctions against those associated with Tsai's US trip and with increased military activity. Between 6 a.m. Sunday and 6 a.m. Monday, a total of 70 planes were detected and half crossed the median of the Taiwan Strait, an unofficial boundary once tacitly accepted by both sides, according to Taiwan's Ministry of National Defense. Among the planes that crossed the median were 8 J-16 fighter jets, 4 J-1 fighters, 8 Su-30 fighters and reconnaissance planes.

That followed a full day between Friday and Saturday, where eight warships and 71 planes were detected near Taiwan, according to the island's Defense Ministry. The ministry said in a statement it was approaching the situation from the perspective of “not escalating conflict, and not causing disputes.” Taiwan said it monitored the Chinese moves through its land-based missile systems, as well as on its own navy vessels. In addition to combat readiness patrols, China's People's Liberation Army would hold “live fire training” in Luoyuan Bay in China's Fujian province opposite Taiwan, the local Maritime Authority announced over the weekend.

China's military harassment of Taiwan has intensified in recent years with planes or ships sent toward the island on a near-daily basis, with the numbers rising in reaction to sensitive activities. Taiwan split with China in 1949 after a civil war. China's ruling Communist Party says the island is obliged to rejoin the mainland, by force if necessary. Beijing says contact with foreign officials encourages Taiwanese who want formal independence, a step the ruling party says would lead to war.