An American climber scaled Taiwan's tallest tower on Sunday, without a safety net or a harness, becoming the first person to do so.

Hundreds of spectators gathered as Alex Honnold, 40, began his journey up the "Taipei 101."

After an hour and a half, Honnold had successfully climbed 1,667 feet (508 meters), uttering the word "sick" as he took in the view. He then rappelled down to his wife Sanni McCandless Hannold.

The risky adventure was captured and broadcast live on streaming platform Netflix.

"Time is finite," Honnold said in a press briefing, adding that people should "use it in the best way." 

Who is Alex Honnold?

The adventurer rose to fame in 2017 after he climbed Yosemite's "El Captain" which is lauded among climbers as the pinnacle of technical difficulty.

Honnold told reporters that it had been a lifelong dream to scale Taipei 101 to his list of achievements.

Honnold said he had considered to scale the building without permission after his first request was denied.

"But ​then ​out of respect for the building and respect for all the people on the team who'd allowed me access to look at it, I was like, well obviously I'm not going to poach this, I'm going to respect the people and just see if it ever comes together," he told reporters. 

"For the project to come together more than a decade later... It's so great. What an opportunity, it is such a pleasure."

Before Honnold, Alain Robert — dubbed the "French Spiderman" scaled the building to reach its peak in 2004. But that was with the use of safety ropes.

Taiwan's President Lai Ching-te congratulated Honnold in a Facebook post on Sunday, branding the challenge "truly moving."

Edited by: Wesley Dockery