President Donald Trump said he made a request for a “substantial portion” of the purchase Tiktok price in a phone call at the weekend with Microsoft’s boss.
He also notified he will prohibit the short-form video app, which is owned by China’s ByteDance, on 15 September if there isn’t a deal.
ByteDance is under pressure to sell its US business after Donald Trump warned a crackdown on Chinese tech companies.
The Trump administration has accused TikTok and others of issuing data to the Chinese government which Beijing and TikTok reject.
“The United States should get a very large percentage of that price, because we’re making it possible,” Mr Trump said.
“It would come from the sale, which nobody else would be thinking about but me, but that’s the way I think, and I think it’s very fair,” he added.
The demand for payment to the US Treasury further complicated deals as legal experts showed that such a request to secure regulatory approval for a takeover deal would be highly unusual.
Nicholas Klein, a lawyer at DLA Piper, said normally “the government doesn’t have the authority to take a cut of a private deal through” the Committee on Foreign Investment in the United States, which is the inter-agency committee that reviews some foreign investments in the US.
Talks over a potential deal seemed to have been delayed on Friday when Trump said he opposed Microsoft buying TikTok’s US business.
While President Donald Trump now giving his agreement to a possible takeover is a major shift in the White House’s position, the tight date for talks is another major obstacle for any potential deal.
TikTok’s US operations “will close down on September 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,” he said.
Also on Monday, White House trade adviser Peter Navarro submitted that Microsoft could shed its holdings in China if it buys TikTok’s US business.
“So the question is, is Microsoft going to be compromised?” Mr Navarro said in an interview with CNN.
He added that: “Maybe Microsoft could divest its Chinese holdings?”
Microsoft verified on Sunday in a blog post that it would carry on discussions on a potential deal with TikTok after a conversation between its chief executive Satya Nadella and Trump.
The technology giant rejected to comment further on the call between Trump and Nadella beyond Sunday’s blog post.
Also on Sunday, US Secretary of State Mike Pompeo said President Trump would do something “in the coming days” in regards of Chinese-owned software companies that he believed acted a national security risk.
Speaking to Fox News, Mr Pompeo also said that the short-form video app TikTok was among those “feeding data directly to the Chinese Communist Party”.
Meanwhile, the state-run China Daily newspaper said on Tuesday that Beijing would reject the “theft” of a Chinese technology company.
The state-backed paper also said in the editorial that China had “plenty of ways to respond if the administration carries out its planned smash and grab”.