House Speaker Nancy Pelosi (D-Calif.) will visit Taiwan during her tour of the Indo-Pacific region, officials from the U.S. and Taiwanese governments confirmed.

Pelosi, who will be the first speaker to visit Taiwan since Newt Gingrich in 1997, arrived in Singapore Monday morning. It is unclear when she expects to land in Taipei, though she does plan to spend the night there.

China has expressed furious opposition to the trip. Foreign Ministry spokesman Zhao Lijian said that China’s military would not “sit idly by” and would “take resolute responses and strong countermeasures to defend its sovereignty and territorial integrity.” One Chinese journalist tweeted that the People’s Liberation Army would be justified in shooting down Pelosi’s plane if she attempted to land in Taiwan, but no Chinese government official has issued a comparable threat.

Reactions in the U.S. were mixed and did not break down along traditional party lines. Sen. Mark Warner (D-Va.) said there were “up and downsides” to the trip but that “the United States needs to stand with Taiwan.” Secretary of State Antony Blinken insisted that the “decision is entirely” Pelosi’s. Fox News host Laura Ingraham shared a Salon article by progressive writer Norman Solomon warning that Pelosi’s visit “could get us all killed.” Right-libertarian author Stephen Kent expressed a different view, tweeting that the Taiwan trip “could be the single most important thing Nancy Pelosi does in her political career” and that “we should all cheer her on.”