China has sent a record number of warplanes across the U.S.-recognized boundary in the Taiwan Strait. The move occurred as Taiwan’s new president considers a potential trip that might include a stop in the United States.

According to Taiwan’s Ministry of National Defense, as of early Thursday, 56 aircraft crossed what is known as the median line. In response, Taiwan deployed its own aircraft, naval vessels, and missile systems. The specifics of Taiwan’s actions were not detailed by the military.

Taiwan’s Ministry of National Defense spokesperson, Sun Li-fang, stated later that day that Taiwan closely monitors the activities in the sea and airspace around the Taiwan Strait, including those of the People’s Liberation Army (PLA) aircraft and ships.

President Lai Ching-te of Taiwan is reportedly considering traveling through the United States while potentially visiting nations that maintain diplomatic relations with Taiwan. Foreign Minister Lin Chia-lung mentioned that the details of the trip were still being planned.

Following a similar visit to the United States by Lai’s predecessor, Tsai Ing-wen, last year, Beijing conducted extensive military exercises. Tsai’s meeting with then-House Speaker Kevin McCarthy during the visit had provoked Beijing’s ire, as it opposes official contacts between Taiwan and countries with which it maintains relations.

China’s recent increase in warplane flights is part of its ongoing pressure campaign since the election victory of President Lai in January. Beijing accuses Lai of advocating for Taiwan’s independence. This campaign has included military drills, diplomatic maneuvers, and legal actions aimed at what China views as separatist activities.

China has consistently asserted its intention to eventually reunify Taiwan, a nation of 23 million people, under its control, using force if necessary.