Earlier this month, US National Security Adviser John Bolton met Taiwan's security chief David Lee, the first such meet between the two sides since 1979 when Washington severed its diplomatic ties with Taipei.
"We firmly oppose any official contact between the US and Taiwan. This position remains unchanged," Chinese Foreign Ministry's spokesperson Lu Kang said here.
"We again urge the US government to abide by the one-China principle and three joint communiques as well as stop any official contact and exchange between the two sides so as to avoid any influences on our bilateral ties and across the board important cooperation."
China sees Taiwan as its breakaway part which needs to be reunited with the mainland one day even by resorting to force if necessary.
Taiwan has been a self-ruled island since 1949 when the Nationalists fled China after losing to the Communists under Mao during the civil war.
Even though the US cut off its diplomatic ties with Taiwan and established relations with China in 1979, it maintains informal with the democratic island.
This irks Beijing and is one of the pesky issues in its ties with the US.
The rare meet has come at a time when tempers between the US and China have frayed in their worsening trade war.
( With inputs from IANS )