A group of US lawmakers arrived in Taiwan Thursday, the second such delegation this month and a fresh sign of American support just days after President Joe Biden invited Taipei to a democracy summit.
International sympathy for Taiwan having a place on the world stage is growing, especially among western nations, as China's authoritarian leader Xi Jinping takes an increasingly bellicose approach towards the island.
China claims self-ruled democratic Taiwan as its territory, to be retaken one day by force if necessary, and has stepped up efforts to diplomatically isolate it.
"When news of our trip broke yesterday, my office received a blunt message from the Chinese Embassy, telling me to call off the trip," Congresswoman Elissa Slotkin, one of the delegates, wrote on Twitter.
Nancy Mace, the only Republican in the group, tweeted her arrival with a selfie and the words: "Just touched down in the Republic of Taiwan".
That choice of wording is significant, because Taiwan's official name is the Republic of China -- but those who favour independence often use the phrase Republic of Taiwan instead.
Beijing baulks at any use of the word "Taiwan", or any references to the island as a "country" and diplomatic gestures that might lend a sense of international legitimacy to the island.
Taiwan is only recognised by 15 other nations but it maintains de facto diplomatic relations with multiple countries.
The latest visit by the lawmakers came after Taiwan was invited to join Biden's planned democracy summit, a move which led to an angry rebuke from Beijing.
It also comes days after China downgraded diplomatic relations with Lithuania because Vilnius allowed Taiwan to open a de facto embassy.