Chinese Foreign Minister Wang Yi has reiterated Beijing's opposition to a possible trip by US House Speaker Nancy Pelosi to Taiwan.

Pelosi arrived in Malaysia on Tuesday on the second stop of her Asian tour. Taiwanese media say she is expected to arrive in Taiwan on Tuesday night.

China's foreign ministry says Wang stressed that Beijing's so-called "one-China Principle" is the core of China's interests, and is an insurmountable red line.

He warned that what he described as the US's betrayal on the Taiwan issue will further bankrupt America's national credibility.

Wang said some US politicians only care about their own interests, and they are playing with fire on the issue of Taiwan, becoming enemies of 1.4 billion Chinese people.

He also warned that if she goes ahead with a visit to Taiwan, it will definitely not have a good outcome.