Chen Binhua, a spokesman for the State Council Taiwan Affairs Office, warned the Taiwan authorities led by Lai Ching-te on Wednesday that their attempts to seek separation with the support of the United States are doomed to fail.

The comments followed a report by the Financial Times on Tuesday, revealing that Washington informed Lai that he would not be allowed to "transit" in New York on his way to South America, where he was reportedly planning to visit Paraguay, Guatemala and Belize.

While Lai's office had not formally announced his trip to Latin America, it said on Monday that he had canceled all overseas travel plans to concentrate on tariff negotiations with the US and relief efforts following a typhoon in southern Taiwan.

Chen said: "We resolutely oppose any form of official exchanges between the US and the Taiwan region of China, and firmly oppose Lai's 'transit' to the US under any pretext or in any form."

He said that the US should adhere to the one-China principle and the three Sino-US joint communiques, exercising extreme caution in handling the Taiwan question and refraining from sending any erroneous signals to separatist forces advocating "Taiwan independence".