Beijing claims self-governing Taiwan as part of its territory, and was angered by increased US support for Taiwan during Donald Trump's administration.
In recent months, China has carried out regular incursions aimed at pressuring Tsai Ing-wen's government to accept Beijing's demand it recognise Taiwan as part of China. These incursions have consisted of just one or two reconnaissance planes in recent weeks.
"Beijing's early signalling to the Biden administration is clearly focused on Taiwan," said Michael Mazza, a visiting fellow at the American Enterprise Institute think tank.
Beijing also announced sanctions on former Trump administration officials.
"The Biden administration appears to be correctly viewing these early moves as tests," Mazza said.
"Statements in response to both the sanctions and the [People's Liberation Army] flights indicate bipartisan support for a resolute approach to China, continuity of comfort with an at-times confrontational relationship, and strong support for allies and partners. Expect more turbulence ahead."
On Saturday, the new US administration urged China to stop pressuring Taiwan, and said it would deepen "our ties with democratic Taiwan".
"Our commitment to Taiwan is rock-solid and contributes to the maintenance of peace and stability across the Taiwan Strait and within the region," Ned Price, US State Department spokesman, said in a statement.
Taiwan's foreign ministry yesterday thanked the US for its support "in the face of Beijing's ongoing coercion".