The naval official, identified by sources as Rear Admiral Michael Studeman, overseeing US military intelligence in the Asia-Pacific region, has made an unannounced visit to Taiwan, two sources told Reuters on Sunday.
Neither Taiwan nor the US has officially confirmed the trip.
Foreign Ministry spokesman Zhao Lijian said China “resolutely opposes” any form of exchanges between US and Taiwanese officials or the two having military relations.
China urges the US to fully recognize the extreme sensitivity of the Taiwan issue, Zhao told a news briefing.
“The Chinese side will, according to how the situation develops, make a legitimate and necessary response,” he said, without elaborating.
Studeman’s visit to Taiwan was an apparent last-ditch effort by the outgoing administration of US President Donald Trump to strengthen relations with the self-ruled island — and a move to outrage China, according to Press TV.
A report on Friday suggested that officials in Taipei and Washington were in talks to schedule a three-day visit to the island by US Environmental Protection Agency administrator, Andrew Wheeler, next month.
Taiwanese Prime Minister Su Tseng-chang confirmed the report, saying Wheeler “will come to Taiwan, to have bilateral discussions on international cooperation on environmental protection issues”.
This would be the third such visit to the island by US officials, this year.
In August, Washington sent Health and Human Services Secretary Alex Azar to Taipei. A month later, Undersecretary of State Keith Krach visited the island.
China reacted with anger on both occasions, describing them as a political stunt aimed at promoting Taiwan’s attempts to gain independence from the mainland.
These official visits deteriorate the already-troubled relations between Washington and Beijing, which are locking horns over a range of issues, including the coronavirus pandemic, trade, the South China Sea, Hong Kong and Tibet.
China, which maintains sovereignty over self-ruled Taiwan, has constantly warned against any official exchanges between Washington and Taipei.
Under the “One China” policy, nearly all countries worldwide — including the US — recognize Beijing’s sovereignty over Taiwan, but under the Trump administration, the US has been courting Taiwan in an attempt to irk Beijing.
In recent controversial remarks that sparked outrage in China, US Secretary of State Mike Pompeo even refused to acknowledge Beijing's sovereignty over Taiwan, saying that the island “has not been a part of China”.
China in response warned Washington of “resolute counterattack” measures, if it kept undermining Beijing’s core interests.
Washington, nevertheless, continues to remain the island’s largest weapons supplier and an avid backer of Taiwan’s secessionist president, Tsai Ing-wen.
The Tsai government signed a $62-billion deal earlier this year to purchase F-16 fighter jets from the US.
The Trump administration has also been lately pushing for the sale of seven large packages of weapons to Taiwan. The packages, including long-range air-to-ground missiles and highly advanced drones, would be one of the largest weapons sales to the self-ruled island in recent years.