Nikki Haley has been urging the U.S. government to ban TikTok, a Chinese-owned social media platform, after some users promoted “Letter to America,” a text written by Osama bin Laden after the Sept. 11 terrorist attacks, while commenting on the war between Israel and Hamas.

Former U.S. ambassador to the United Nations under President Donald J. Trump, Ms. Haley argued that the circulation of the document was an example of foreign adversaries using social media to spread anti-American propaganda to young people.

“That’s why you have to ban TikTok,” Ms. Haley said at a town hall in Newton, Iowa, on Friday. “Nepal just came out yesterday, and they’re banning it because they see what’s happening in their country. India did it. Why are we the last ones to do it?”

In bin Laden’s letter, he defended the terrorists’ actions during the attacks on the World Trade Center and the Pentagon, pointing fingers at American taxpayers for harming Muslims in the Middle East. He also mentioned the control exerted by Jews over the American economy and media. TikTok responded to Ms. Haley’s calls for a ban by stating that the circulation of bin Laden’s letter violated the platform’s rules banning support for terrorism.

A spokesman for the company told The New York Times on Thursday that most of the views of the videos came after news organizations wrote about them, and that the letter had also “appeared across multiple platforms and the media.”

Ms. Haley’s crusade against TikTok has become a flashpoint in the Republican presidential race. At a Republican debate in Miami, she clashed with Vivek Ramaswamy, the biotech entrepreneur, over calls for a TikTok ban. She has also contended that social media platforms should better police certain users and content.

Ms. Haley has assailed what she calls “foreign infiltration” into American society by hostile governments, focusing on propaganda and disinformation being distributed by China, Russia, and Iran through TikTok and other social media platforms. She has also drawn attention to Chinese investments in various communities across the country, particularly in rural states like Iowa.

Linda Schroeder, of Dubuque, supported Ms. Haley’s focus on the issue by saying, “Why are we allowing it? For them to be here,” Ms. Schroeder said after hearing from Ms. Haley. “I grew up with 14 other siblings on a farm, and we still have the farm, and we’ll keep it.”