Beijing has rescinded a pledge not to send troops to Taiwan if it takes control of the island and accused the U.S. of trying to "undermine China’s development and progress" in a new policy document.

The big picture: Beijing's first white paper on Taiwan since Xi Jinping became president comes days after China's military held live ammunition drills near the democratically governed island in protest at House Speaker Nancy Pelosi's visit to the capital, Taipei.

In the paper, titled "The Taiwan Question and China's Reunification in the New Era" and published Wednesday, Beijing claims that "a small number of countries, the U.S. foremost among them," are "using Taiwan to contain China."

Flashback: The previous two policy documents on Taiwan that the ruling Chinese Communist Party issued in 1993 and 2000 both stated that it "will not send troops or administrative personnel to be based in Taiwan" in its planned "reunification" of the island it regards as a breakaway province, per Reuters.