Keith Krach, the US under-secretary for state, kept a low profile at the service honouring the man who led Taiwan’s transition to democracy.
Mr Krach’s presence at the event and on the island has drawn a strong rebuke from China, which sent 18 warplanes across the mid-line of the Taiwan Strait on Friday in an unusually large display of force.
On Saturday, Beijing dispatched 19 more warplanes, two of which were bombers, according to Taiwan’s defence ministry.
The island’s air force scrambled its own planes and deployed an air defence missile system to monitor China’s activities, according to a statement.
The service was held at the Aletheia University in Taipei on Saturday morning, with President Tsai Ing-wen honouring Mr Lee for bringing a peaceful political transition to the island democracy.
Mr Lee had built a separate Taiwanese political identity, distinct from mainland China, which claims Taiwan as part of its own territory to be reunited by force if necessary.
His carving out of a non-Chinese identity and insistence that the island be treated as an equal country brought him into direct conflict with Beijing.
He died on July 30 at age 97.
Ms Tsai said: “We have a responsibility to continue his endeavours, allowing the will of the people to reshape Taiwan, further defining Taiwan’s identity and deepening and bolstering democracy and freedom.”
Former Japanese prime minister Shinzo Abe and the Dalai Lama also paid tribute from afar.
“We Buddhists believe in life after life, so most probably he will be reborn in Taiwan,” the Dalai Lama said in a video message. “His rebirth will carry his spirit continuously.”
The guests included another former Japanese prime minister, Yoshiro Mori.
Mr Lee, an agricultural economist and politician, devoted his career toward building democracy on the island through direct elections and other changes.
He was the first government official to speak out and formally apologise for the so-called 228 incident, named after an incident on February 28, 1947, when soldiers under the Kuomingtang, or the sole ruling Nationalist Party, shot and killed thousands of civilians in an anti-government uprising.
The bloodshed marked the beginning of a decades-long period known as the White Terror in which the island was ruled by martial law.
In 1990, Mr Lee signalled his support for student demands for direct elections of Taiwan’s president and vice president and the end of reserving legislative seats to represent districts on the Chinese mainland.
The following year he oversaw the dismantling of emergency laws put into effect by Chiang Kai-shek’s government, effectively reversing the Nationalists’ long-standing goal of returning to the mainland and removing the Communists from power.
China launched a series of threatening military manoeuvres off the coast of mainland Fujian province that included the firing of missiles just off Taiwan’s coast.
More missiles were fired immediately before the March 1996 presidential elections, and the US response was to send aircraft carrier battle groups to Taiwan’s east coast in a show of support.
The Trump administration has taken multiple steps in recent months to strengthen its engagement with Taiwan, angering China.
Mr Krach is the second high-level official to visit Taiwan in two months, following US health secretary Alex Azar in August.
An editorial in the Chinese Communist Party newspaper Global Times said on Friday: “Every time a high-ranking US official visits Taiwan, the fighter jets of the PLA (People’s Liberation Army) should be one step closer to the island.
“The US and Taiwan must not misjudge the situation, or believe the exercise is a bluff. Should they continue to make provocations, a war will inevitably break out.”
