A giant Taiwan flag suspended beneath a US-made Chinook helicopter flew over Taipei as part of the island’s national day celebrations, in a display that defies Beijing’s objections to Taiwan’s international visibility.

Since 2019, Taiwan’s army has flown the massive flag beneath a tandem-rotor Chinook CH-47SD helicopter over the presidential office each year as the national anthem is sung during the October 10 celebrations. The tradition aims to promote unity amid growing pressure from China.

The flag display is among the most eye-catching moments of the celebrations, as Taiwan faces restrictions on displaying its flag internationally because of Beijing’s objections.

President Lai Ching-te is scheduled to deliver a keynote address on Saturday morning, outlining his policy objectives and addressing relations with China.

China, which views democratically governed Taiwan as its own territory, has ratcheted up efforts to stop countries engaging with Taipei, including preventing Taiwan's flag from appearing at sports events such as the Olympics, where it competes as "Chinese Taipei" and uses a different, custom-designed emblem.

Neither government formally recognises the other.

China's Taiwan Affairs Office did not respond to a request for comment on Taiwan's national day celebrations. Following Lai's speech last year, Beijing called him "a troublemaker, creator of danger and a war-maker".

One of the helicopter pilots taking part in rehearsals this week, 40-year-old Lin Chang-cheng, told Reuters that the flag is a "concrete symbol of national sovereignty".

"This is especially true given that we have actually suffered a lot of suppression in the international community, so when we see the national flag being displayed, it's an extremely moving moment," he said at Taipei's downtown Songshan airport.

Taiwan's national day is held on the anniversary of a 1911 uprising that led to the overthrow of China's last imperial dynasty and the establishment of the Republic of China.

The Republic of China government fled to Taiwan in 1949 after losing a civil war with Mao Zedong's communists, who proclaimed the People's Republic of China. Republic of China remains Taiwan's formal name.

Suspended from a long, weighted cable beneath the helicopter, the 12-metre-by-18-metre (40-feet-by-60-feet) Republic of China flag is made out of the same tough, light-weight material used for parachutes.

While the flag is a contested symbol even within Taiwan, especially for those who champion an entirely separate identity from China, catching sight of it flying over Taipei is exciting for those watching from the city's hills.

"When I see the Taiwan flag, I feel that it represents freedom, democracy and freedom of speech," said Hsiao Shao-chun, 44, watching rehearsals on Taipei's outskirts.

During the Cold War, national day celebrations in Taiwan were heavily military focused, with speeches about "retaking the mainland".

These days, the event is more about showcasing Taiwan's soft power and global visibility, including a fireworks display at Taipei 101, one of the world's tallest buildings.