Taiwan scrambled fighter jets Friday as the Chinese military conducted exercises near the Taiwan Strait during a rare visit by a high-ranking US diplomat to the self-ruled island.
According to Taipei's defence ministry, 18 Chinese aircraft -- including bombers and fighters -- entered Taiwan's southwest air defence identification zone (ADIZ) and also crossed the so-called median line that divides the Taiwan Strait.
Taiwan's military "scrambled fighters, and deployed its air defence missile system to monitor the activities", the ministry said.
The exercises came after Keith Krach, US undersecretary of state for economic growth, energy and the environment, landed in Taipei on Thursday for a three-day visit, the highest-ranking State Department official to visit in 40 years.
China's Communist leadership baulks at any recognition of Taiwan -- which has been ruled separately from China since the end of a civil war in 1949 -- and has pursued a decades-long policy of marginalising the democratic island.
Beijing considers Taiwan part of its territory, to be absorbed into the Chinese mainland -- by force if necessary.
Relations between the United States and China are also at their lowest point in decades, with the two sides clashing over a range of trade, military and security issues as well as the coronavirus pandemic.
At a press conference Friday, a Chinese defence ministry spokesman said Beijing was "holding actual combat exercises near the Taiwan Strait" when asked how it would respond to Krach's visit.
"This is a legitimate and necessary action taken to safeguard China's sovereignty and territorial integrity in response to the current situation in the Taiwan Strait," Ren Guoqiang told reporters.
Ren also warned that the Chinese military had "sufficient ability" to counter any external threat or challenge from Taiwan separatists.
- 'Causing trouble' -
Ren accused the United States of "frequently causing trouble" over Taiwan, which he said "is purely China's internal affairs, and we won't tolerate any external interference".
US Secretary of State Mike Pompeo hit back, accusing China of "military blustering."
In recent weeks, Taiwan has reported a sharp rise in incursions by Chinese warplanes into its ADIZ.
"We hope the other side can exercise restraint and not... heighten conflicts between the two sides. These military intimidations have caused resentment among the Taiwanese people," its defence ministry said in a statement Friday.
Chinese jets also made a brief incursion across the midline of the strait in August, as US health chief Alex Azar made his country's highest-level visit to Taiwan since 1979 -- the year Washington switched diplomatic recognition to Beijing.
Washington's increased outreach to Taiwan under President Donald Trump has become yet another US-China flashpoint.
The US said Krach was visiting Taiwan to attend Saturday's memorial service for late former president Lee Teng-hui, who died in July aged 97.
On Friday, Krach met with foreign minister Joseph Wu to discuss bilateral issues and exchange views on future collaborations, according to Taipei authorities. He is also scheduled to join President Tsai Ing-wen for dinner at her official residence.
China has ramped up pressure on Taiwan since Tsai came to power in 2016, as she refuses to acknowledge its idea that the democratic island is part of "one China".
On Friday, an editorial in the nationalist, Chinese state-backed Global Times newspaper warned "war will inevitably break out" if the US and Taiwan continue to "make provocations."