TAIPEI - U.S. House of Representatives Speaker Nancy Pelosi arrived in Taiwan late on Tuesday, starting a visit that Beijing had warned her against taking, saying it would undermine Sino-U.S. relations.

Pelosi was on a tour of Asia that includes announced visits to Singapore, Malaysia, South Korea and Japan.

China claims self-ruled Taiwan as its own, and a foreign ministry spokesman said earlier this week that any visit by Pelosi would be "a gross interference in China's internal affairs" and warned that "the Chinese People's Liberation Army will never sit idly by."

(Reporting by Sarah Wu and Yimou Lee, Writing by Tony Munroe; Editing by Frank Jack Daniel)