Officials in Beijing, which claims sovereignty over self-governing Taiwan, were furious. They have now asked the U.S. to prevent Tsai from using New York City as a stopover en route to scheduled meetings in Guatemala and El Salvador early next month, according to a Foreign Ministry statement sent to Reuters.

China hopes the U.S. “does not allow her transit, and does not send any wrong signals to ‘Taiwan independence’ forces,” read the statement.

Tsai belongs to the Democratic Progressive Party, which officially backs independence for Taiwan. She has discreetly shied away from discussing the topic since her presidential campaign, but she and the DPP remain deeply distrusted in Beijing.

A State Department spokeswoman told Reuters that stopovers would continue “based on long-standing U.S. practice, consistent with the unofficial nature of our relations with Taiwan.”