TikTok CEO Shou Di Chew is reportedly scheduled to attend President-elect Donald Trump's pre-inauguration rally in Washington, D.C. Sunday (January 19) amid the social media platform's ban in the United States, two sources familiar with the event confirmed to ABC News Sunday morning.

The U.S. ban on TikTok went into effect Sunday morning, months after Congress passed a bipartisan bill granting the social media application a 270-day window to cut ties with its China-based parent company ByteDance as an ultimatum. TikTok, instead, attempted to pursue a legal challenge on First Amendment grounds, which failed at the Supreme Court on Friday (January 17).

Trump, who launched his own TikTok account last June, said he hasn't made a final decision, but was considering a 90-day extension of the deadline for a sale once he took office on Monday (January 20).

“I think that would be, certainly, an option that we look at. The 90-day extension is something that will be most likely done, because it’s appropriate. You know, it’s appropriate. We have to look at it carefully. It’s a very big situation,” Trump said in the phone interview with NBC News.

“If I decide to do that, I’ll probably announce it on Monday,” he added.

TikTok also acknowledged that Trump was considering a solution for reinstatement upon taking office in its ban message Sunday morning.

"We are fortunate that President Trump has indicated that he will work with us on a solution to reinstate TikTok once he takes office," the message stated. "Please stay tuned!"

Colorado's Morning News with Marty Lenz & Jeana Gondek