The move by U.S. government officials comes as China has stepped up military action around the island.
"There is zero room for compromise and not an inch to give," Chinese spokesperson Zhao Lijian told reporters Tuesday. "We urge the U.S. side to grasp the situation, earnestly abide by the one-China principle and the three China-US joint communiqués, refrain from playing with fire, immediately stop official contact with Taiwan in any form."
The spokesman warned against sending the "wrong signals to Taiwan 'independence forces' so as not to subversively influence and damage Sino-U.S. relations and peace and stability across the Taiwan Strait."
While the U.S. officially recognizes Beijing and a "one China" policy, Washington is legally bound to supply Taiwan with arms to defend itself under the 1979 Taiwan Relations Act.
On Friday, the State Department issued new "liberalized" guidance on how the U.S. will broaden and deepen its unofficial relations with Taiwan.
"Our support for Taiwan is rock solid," a State Department spokesperson told Fox News. "We are committed to deepening our ties with Taiwan – a leading democracy and a critical economic and security partner."
The new guidelines allow for increased communication between the U.S. and Taiwan – a move that could further strain U.S.-China relations, as tensions in the region are on the rise.
China has been pushing boundaries by continuing to send aircraft and jets into Taiwan’s air defense identification zone (ADIZ), prompting the U.S. Navy to send a guided-missile destroyer into the Taiwan Strait last week for "routine" transit, reported Reuters.
On Monday, 22 Chinese aircraft, including fighter jets and nuclear-capable bombers, flew over Taiwan’s ADIZ, reported Taiwan News.