Trump also said the federal government will have to be paid a “substantial amount of money” as part of any 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 at the White House on Monday. “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.”

Trump set off a furious scramble over the fate of the Chinese-owned app on Friday, when he said he would ban the company’s operations through an executive action on Saturday. But the weekend passed without any official move from the White House, after the president spoke with Microsoft Chief Executive Officer Satya Nadella about his company’s efforts to purchase the viral video application.

Microsoft said in a blog post that it was aiming to complete a deal for TikTok’s operations in the U.S., as well as in Canada, Australia and New Zealand, no later than Sept. 15. The White House had insisted upon that deadline, according to people familiar with the matter. It could prove an uphill climb, with key details for the deal — including price — still not worked out, people familiar with the discussions said.

Trump told reporters on Monday: “Whatever the price is that goes to whoever owns it — because I guess it’s China, essentially, more than anything else — I said a very substantial portion of that price is going to have to come into the treasury of the United States.”

Trump questioned who would get rights to the company’s name if TikTok is owned by two different companies. “My personal opinion was they would be better off buying the whole thing rather than buying 30% of it,” Trump said. “I think buying 30% is complicated.”

The White House has said it’s concerned that TikTok’s parent company, ByteDance Ltd., could be compelled to hand over American users’ data to Beijing or use the app to influence the 165 million Americans, and more than 2 billion users globally, who have downloaded it. And Trump has looked to ratchet up pressure on China ahead of November’s election, frustrated by slow implementation of the trade pact inked earlier this year and the spread of the coronavirus for which he blames China.

Trump said Monday that TikTok “can’t be controlled for security reasons by China. Too big, too invasive, and it can’t be.”

Teenagers opposed to Trump have also used the app to disrupt the president’s campaign activities, including signing up for tickets to his first rally since the beginning of the pandemic, in Tulsa. Attendance at the late June event was far below expectations, and Trump hasn’t held another rally since.

In its blog post, Microsoft pledged to add more security, privacy and digital safety protections to the TikTok app and ensure that all private data of Americans be transferred back to the U.S. and deleted from servers outside the country. The company also said it may invite other American investors to take minority stakes in the company.

“Microsoft fully appreciates the importance of addressing the President’s concerns,” the company said. “It is committed to acquiring TikTok subject to a complete security review and providing proper economic benefits to the United States, including the United States Treasury.”

Still, U.S. lawmakers and administration officials have favored shutting down the application altogether to send a message to China after Beijing restricted American companies like Facebook Inc., Twitter Inc. and Alphabet Inc.’s Google. White House adviser Peter Navarro on Monday said in a pair of interviews with CNN and Fox News that he wasn’t sure Microsoft was the right company to buy TikTok’s U.S. operations, saying it had helped China construct its internet firewall.

“Should we trust any company that operates in China?” Navarro told Fox News.