After two days on the social-media app, the US president has 11,000 followers.
TikTok was banned in India two months ago. Mr Trump wants to follow suit unless it sells the app's US version and has signed executive orders targeting both it and another Chinese social-media app, Tencent's WeChat.
Both India and the US fear data collected by the TikTok could be given to the Chinese government.
TikTok strongly denies this and says none of its international users' data is stored in China.
Nevertheless, Microsoft is currently in negotiations with TikTok to buy all or part of the company.
Meanwhile, Mr Trump's team has published four Triller videos.
The first, claiming he is a "professional at technology", has amassed 6.1 million views.
In the others, the president thanks "Boaters for Trump" and references his election opponent, Joe Biden.
Despite launching in 2016, a year later than Triller, TikTok is estimated to have been downloaded more than two billion times, compared with its US rival's 250 million.
But another US app, Byte, is also a rival and Facebook has set up a similar platform called Reels.