China strongly deplores and firmly opposes the United States allowing Lin Chia-lung to visit New York, Foreign Ministry spokesman Guo Jiakun said on Thursday.

By allowing the visit of Lin, head of the Taiwan region's so-called foreign affairs department, during the United Nations General Assembly, the US has provided a platform for "Taiwan independence" separatist forces to pursue their agenda, Guo said at a regular news conference.

"This is a brutal interference in China's internal affairs, undermines seriously the one-China principle and the stipulations in the three China-US joint communiques, and sends a seriously erroneous signal to 'Taiwan independence' separatist forces," Guo said.

It's "all too obvious" that the Democratic Progressive Party authorities sent Lin to New York in an attempt to seek the US support for "Taiwan independence", he said, warning the DPP authorities that any provocative move to seek "Taiwan independence" will backfire.

Guo also noted Lin's interactions in New York with countries that have so-called diplomatic ties with Taiwan, urging these countries to "avoid being repeatedly manipulated and used by 'Taiwan independence' separatist forces".

These countries should understand clearly that the one-China principle is where global opinion trends, and "there is no future for tying oneself with 'Taiwan independence' forces", he said.

"The international commitment to the one-China principle cannot be changed. China's reunification will not be stopped," Guo added.