China considers Taiwan a breakaway province which it seeks to unify with the mainland one day. The United States has committed to help Taiwan but has not specified the extent of that help.
US House Speaker Nancy Pelosi has made criticism of China and support for Taiwan a key focus in her more than three decades in Congress.
The statement issued by the Cabinet's Taiwan Affairs Office and its news department followed almost a week of missile firings and incursions into Taiwanese waters and airspace by Chinese warships and air force planes.
US House Speaker Nancy Pelosi, who is leading the trip with five other members of Congress, also met with representatives from Taiwan's legislature.