According to a transcript of a May 28 interview with Time, Biden said he would not rule out the possibility of using US military force in the case of a Chinese invasion of Taiwan.
"We call on the United States ... to stop sending any form of erroneous signals to pro-Taiwanese separatist forces," Mao told reporters.
Taiwan has been governed independently of mainland China since 1949. Beijing views the island as its province, while Taiwan maintains that it is an autonomous country, but avoids declaring independence. China opposes any official contacts of foreign states with Taipei and considers Chinese sovereignty over the island indisputable.