TAIPEI/WASHINGTON/BEIJING (REUTERS, BLOOMBERG) - A two-star Navy admiral overseeing US military intelligence in the Asia-Pacific region has made an unannounced visit to Taiwan, two sources told Reuters on Sunday (Nov 22), in a high-level trip that could vex China.
The sources, who include a Taiwanese official familiar with the situation, said the official was Rear-Admiral Michael Studeman.
The sources spoke on condition of anonymity.
According to the Navy's website, Studeman is director of the J2, which oversees intelligence, at the US military's Indo-Pacific Command.
The Pentagon declined comment, as did Taiwan's Defence Ministry.
Taiwan's foreign ministry confirmed on Sunday that a US official had arrived in Taiwan but declined to provide details, saying the trip had not been made public.
Beijing, which views Taiwan as its territory, has condemned the high-level US visit.
Chinese Foreign Ministry spokesman Zhao Lijian told a daily briefing on Monday that Beijing would "take necessary and justified response in accordance with the development of the situation", without elaborating.
"We urge the US to recognise the highly sensitive nature of the Taiwan question, abide by the one-China principle and three joint communiques and stop any official ties and military contacts with Taiwan," Mr Zhao said.
China, which claims democratically-run Taiwan as its own territory, reacted with fury when US Health Secretary Alex Azar came to Taipei in August, followed by US Undersecretary of State Keith Krach in September, sending fighter jets near the island each time.
The Trump administration has ramped up support for Taiwan, including with new arms sales, alarming China.
It was not immediately clear whether Studeman's visit would be seen as an escalation by Beijing.
Still, he could be one of the most high-ranking US military officers known to have visited Taipei in recent years.
Douglas Paal, a former head of the US representative office in Taiwan who is now with the Carnegie Endowment for International Peace, said: "If it is Indopacom J2 Studeman, I know of no precedent for such a visit."
But Randall Schriver, a former assistant secretary of defence for Asia during the Trump administration, said Trump's Pentagon had been quietly sending one-star flag officers to Taiwan on a routine basis.
He noted that the United States and Taiwan had close intelligence exchanges on the threat from China's military.
Bonnie Glaser, a regional security expert at Washington's Centre for Strategic and International Studies think-tank, said it would not be unprecedented for a US flag officer to visit Taipei.
Taiwan's United Daily News published pictures of an unmarked private jet, which it identified as being a US military aircraft, arriving at Taipei's downtown Songshan airport, and what appeared to be officials waiting at its VIP terminal.
Data on the flight-tracking website planefinder.net showed a private flight arriving from Hawaii - home to the headquarters of the Indo-Pacific Command - into Songshan airport late Sunday afternoon, shortly before the United Daily News published the pictures on its website.
In a brief statement, Taiwan's Foreign Ministry said there were frequent interactions with the United States and that "we welcome the visit of the US official."
"But as this itinerary has not been made public, based on mutual trust between Taiwan and the United States, the Foreign Ministry has no further explanation or comment," it added.
However, it said in a separate statement that Taiwan media reports that a delegation led by CIA chief Gina Haspel had arrived in Taiwan were untrue, and that Haspel had no plans to come.
The de facto US embassy in Taipei declined to comment.
The United States, like most countries, has no formal diplomatic ties with Taiwan, but is the democratic island's most important international backer and supplier of arms.
Taiwan Premier Su Tseng-chang said last week the Cabinet-level head of the US Environmental Protection Agency, Andrew Wheeler, will visit Taiwan.
US media said that trip is likely next month.