Beijing is "positioning itself" to respond to a potential visit to Taiwan by House Speaker Nancy Pelosi with "military provocations," such as firing missiles into the Taiwan Strait or breaching Taiwan's Air Defense Identification Zone, National Security Council spokesperson John Kirby said Monday.

Why it matters: Kirby did not confirm Pelosi's travel plans, but Taiwanese and international outlets have confirmed that she's expected to arrive on Tuesday night local time. China's Foreign Ministry on Monday repeated its threat of "serious consequences" if Pelosi does stop in Taipei.

• “The potential visit, if made, will be a gross interference in China’s internal affairs and severely undermine China’s sovereignty and territorial integrity, trample on the One China Principle, and undermine U.S.-China relations. It will lead to a very serious... consequences," spokesperson Zhao Lijian said.
• He added that China's military will "never sit idly by" and will take "strong and resolute measures.”
• China has already announced military exercises in the South China Sea from Tuesday to Saturday.

Context: Beijing has vowed to take control of the self-governing island, by force if necessary, and reacts furiously to any gestures that seem to treat Taiwan as an independent state.

• Pelosi would be the highest-ranking U.S. official to visit since 1997 and her planned visit comes at a sensitive time for President Xi Jinping, who is preparing to seek a third term at the upcoming Communist Party congress.
• Beijing's readout of Xi's call with President Biden last Thursday said he'd warned the U.S. president not to "play with fire" over Taiwan.
• Kirby said Monday that Biden had told Xi on the call that Congress is independent of the White House and Pelosi "makes her own decisions" (though Kirby confirmed that she is traveling on a military aircraft, as is typical on such trips).
• He added that Pelosi has "the right to visit Taiwan" and promised that her safety would be ensured throughout her trip. 

What they're saying: Kirby repeatedly argued that the visit, if it happens, would not be without precedent, as then-Speaker Newt Gingrich traveled to Taiwan in 1997 and numerous lower-ranking U.S. lawmakers have visited more recently.

• But Biden himself helped focus attention on the trip when he publicly warned on July 21 that the U.S. military thought it was "not a good idea right now."
• Kirby contended that Pelosi's visit would not alter the status quo or signal any change in U.S. policy, while "Beijing's actions could have unintended consequences that only serve to increase tensions."
• Pelosi has kept quiet about her trip, which is expected to include a meeting on Wednesday with Taiwan President Tsai Ing-wen. Pelosi tweeted an itinerary of her travels in Asia on Sunday but made no mention of Taiwan.