President Trump declared on Monday that the clock is ticking down on TikTok.

He said the Chinese-owned video-sharing service, hugely popular with teenagers, will be shut down in the U.S. if Microsoft or some other American company doesn’t buy TikTok’s U.S. operations by Sept. 15.

He added the startling claim that the U.S. Treasury should receive “a very substantial portion” of the eventual sale price.

It’s unclear whether Trump has the power to enforce such a deadline, or to insist that the Treasury get a big slice of the purchase price.

Microsoft is preparing to negotiate with TikTok’s Chinese parent company, ByteDance, to buy the social media app, which is “used to create short dance, lip-sync, comedy and talent videos,” says Axios.

U.S. officials have grown increasingly concerned about TikTok’s seeming lack of security and privacy protection.

They worry that China’s communist government will compel ByteDance to hand over data from the 165 million Americans who have downloaded the app. About 100 million, nearly all of them young people, are thought to be regular users.

Although Microsoft appears to be the only U.S. company actively working on what could be a purchase totaling $50 billion or more, Trump says that’s not important — so long as the buyout is complete by Sept. 15.

There’s been some speculation that Amazon might take an interest in such a deal.

“I don’t mind whether it’s Microsoft or someone else, a big company, a secure company, a very American company buys it,” Trump told reporters on Monday, reports the Boston Globe.

It’ll close down on Sept. 15 unless Microsoft or somebody else is able to buy it and work out a deal, an appropriate deal, so the Treasury of the United States gets a lot of money,” the president said.

Axios analyst Dan Primack says it’s “abnormal” for a president “to dictate the timeline (and maybe terms) of a U.S. company-led acquisition.”

As for the demand for “a lot of money” to let the deal go through, that skates “very close to announcing extortion,” Axios says, citing Primack.

In any event, the prospective sale of the TikTok app to an American company has significant bipartisan support in Congress.

Rep. Kevin McCarthy (R-CA), the House Minority Leader, and Sen. Chuck Schumer (D-NY), minority leader in the Senate, have made it clear they and others in their parties would like to see Microsoft acquire TikTok’s U.S. service, Reuters reports.

Microsoft says CEO Satya Nadella has spoken with Trump and “is prepared to continue discussions to explore a purchase of TikTok in the United States” by Sept. 15.

Microsoft is expected to extend those negotiations to include the potential purchase of  TikTok in Canada, Australia and New Zealand.