The private equity giant Blackstone is weighing taking a small stake in TikTok ahead of an April 5 deadline set by President Trump for the Chinese-owned app to change its ownership or face a U.S. ban under federal law, two people familiar with the situation said.

Investing in TikTok would give Blackstone the chance to take a bite of one of the most popular social media applications in the world, which has over 170 million American users. It is unclear if any investment — which would likely be a fraction of the size of Blackstone’s typical deals — will move forward, and other investors are also circling the app, which is owned by the Chinese internet giant ByteDance, four people familiar with the talks said.

If an investment happens, it could boost favor with President Trump, who has made it a mission to save TikTok from disappearing under the federal law. Last year, Congress passed the law that forces a sale of the app because of national security concerns related to its Chinese ownership.

Mr. Trump extended the deadline for a deal in January, and has suggested he could do so again if an agreement isn’t reached next week. He also suggested this week that he might relax upcoming tariffs on China in exchange for the country’s support of a deal.

Blackstone’s talks add to TikTok’s chaotic history in the United States. The video app has repeatedly wriggled out of political efforts to shut it down in the country. In January, the app went dark in the United States for about 12 hours before flickering back to life. A spokesperson for Blackstone said the firm did not comment on deal speculation. Neither TikTok or the White House responded to requests for comment. Reuters earlier reported Blackstone’s interest.

As April 5 approaches, discussion about potential suitors for the app has intensified. Mr. Trump has been repeatedly approached by parties pitching him ideas, and his interest in different arrangements can be fleeting, two other people close to the talks say.