Trump once backed a TikTok ban. Now he's joined the app as he races Biden for young voters.

• Trump has joined TikTok — nearly four years after he sought to ban the app in the US as president.
• "It's my honor," the ex-president said in his first video.

As president, Donald Trump wanted to ban TikTok for its alleged ties to the Chinese government.

But on Saturday, the ex-president became one of the platform's newest users, expanding his online reach to young people ahead of November.

By early Sunday afternoon, Trump had amassed 2.1 million followers and his first video — taken at an Ultimate Fighting Championship event in Newark last night — had amassed over 2.5 million likes.

The video kicks off with remarks by UFC President Dana White as he points to Trump: "The president is now on TikTok."

Trump's response: "It's my honor."

The Trump campaign was just as ebullient over the development.

"We will leave no front undefended and this represents the continued outreach to a younger audience consuming pro-Trump and anti-Biden content," Trump spokesman Steven Cheung said in a statement.

Trump's newfound fondness for TikTok comes nearly four years after he signed an executive order that would have forced TikTok to sell to an American company. TikTok sued and the order was struck down in courts.

President Joe Biden — whose reelection campaign also launched a TikTok account — similarly signed legislation in April that could lead to a national TikTok ban if China-based parent company ByteDance chooses not to divest itself of the app.

TikTok has roughly 170 million users in the United States, and both Biden and Trump are angling to reach its young-skewing audience ahead of November.

While Biden easily won over voters aged 18 to 29 in the 2020 presidential election, issues like inflation and Gaza have hampered his campaign this year.