Chinas foreign ministry on Sunday condemned a brief visit by Taiwan Vice President William Lai to the United States.
"China firmly opposes any form of official interaction between the US and the Taiwan region," a ministry spokesperson said in a statement.a
The ministry also condemned the US decision to arrange the stopovers that it said undermined Chinas "sovereignty and territorial integrity."
"China is closely following the developments of the situation and will take resolute and strong measures to safeguard its sovereignty and territorial integrity," the ministry said.
Lais stopovers in New York and California are scheduled to take place on his way to and from Paraguay for the inauguration of its new president. Lai is also the presidential candidate of Taiwans ruling Democratic Progressive Party and the elections front-runner.