The United States sent its Palau ambassador to Taiwan this week, in a rare visit by a serving diplomat that has riled Beijing as Washington seeks to counter China's growing influence in the Pacific.
Ambassador John Hennessey-Niland is accompanying Palau President Surangel Whipps who is in Taiwan to launch a travel bubble with the island.
Palau is one of only 15 nations that officially recognise Taiwan over China, which views the self-ruled democratic island as its own territory and has vowed to one day seize it.
The presence of a US ambassador on the visit has ruffled Beijing's feathers, with the foreign ministry on Monday saying it opposed Hennessey-Niland's trip.
Democratic Taiwan lives under the constant threat of invasion by authoritarian China, which has stepped up military, diplomatic and economic pressure since the 2016 election of President Tsai Ing-wen.
Speaking to reporters in Taipei on Tuesday, Hennessey-Niland took the unusual step of referring to Taiwan as a country, a characterization Beijing bristles at.
"I know that here in Taiwan people describe the relationship between the United States and Taiwan as real friends, real progress and I believe that description applies to the three countries -- the United States, Taiwan and Palau," he said.
He then posed for photos with Whipps, Taiwan's foreign minister Joseph Wu and US de facto ambassador to Taiwan Brent Christensen.
Washington has remained Taipei's most important unofficial ally and its leading arms supplier despite switching diplomatic recognition to Beijing in 1979.
It maintains de facto diplomatic relations through the American Institute in Taiwan, a government-sponsored non-profit.
Historically it avoided sending serving State Department diplomats to Taiwan.
That changed under former President Donald Trump, who ramped up official contacts and lifted restrictions on how American diplomats could interact with their Taiwanese counterparts.
Last year, then health chief Alex Azar became the highest-ranking US official to visit Taiwan since 1979, followed by a senior diplomat's visit a month later.
President Joe Biden has so far maintained similar overtures.
The US has sent warships to sail through the Taiwan Strait thrice since he took office in January. Last week, Taipei and Washington inked a memorandum on coastguard cooperation.
China's sabre-rattling towards Taiwan has increased considerably under President Xi Jinping.
Last year a record 380 incursions were made by Chinese planes into Taiwan's air defence zone.
On Friday, 20 Chinese military aircraft, including 12 fighters, made one of the largest incursions to date.
Hennessey-Niland's trip comes as Washington tries to push back against China's growing clout in the Pacific, Sung Wen-ti, a lecturer in Taiwan studies at the Australian National University, said.
"As the Pacific community's unity wanes, it opens up greater space for Chinese diplomatic offensives to win hearts and minds in the region," he told AFP.
Beijing has poached seven of Taiwan's diplomatic allies, including two in the Pacific, as its growing influence in the region has caused concern in Australia and New Zealand.