House Speaker Nancy Pelosi, D-Calif., landed in Taiwan late Tuesday evening local time,
and she is expected to meet members of Taiwan's legislature and President Tsai Ing-wen on Wednesday,
according to a source familiar with planning for her visit.
The highly-anticipated stop has faced stark warnings from China,
in turn worrying the White House that it could trigger a crisis in the Taiwan Strait and worsen already tense U.S.-China relations.
China sent two Su-35 fighter jets across the Taiwan strait ahead of Pelosi's arrival,
according to state broadcaster CCTV, and the spokeswoman for China's foreign ministry said on Twitter,
"The US & Taiwan have made provocations together first, whereas China has been compelled to act in self-defense."
The visit was not announced in advance, and it comes as part of Pelosi's tour of Asia,
including Singapore, Malaysia, Japan and South Korea, where she has been leading a small congressional delegation.
She is the highest-ranking elected American official to visit Taiwan since then-Speaker Newt Gingrich in 1997.
The source familiar with planning for Pelosi's visit says she will be given an award by Taiwan's president and visit a museum before departing on Wednesday.
The island democracy governs itself, but China claims it as its territory.
Rumors of Pelosi's visit launched a geopolitical firestorm amid escalating tensions between the U.S. and China.