The Donald Trump administration said on Friday that it would bar the Chinese-owned mobile apps WeChat and TikTok from US app stores as of Sunday, striking a harsh blow against two popular services used by more than 100 million people in the US.

Both apps are among the over 200 mobile applications already banned by the Indian government in the aftermath of the heightened border tensions with China in Ladakh.

The restrictions will ban the transferring of funds or processing of payments through WeChat within the US as of Sunday. In the case of WeChat, the restrictions will also prevent any company from offering Internet hosting, content delivery networks, Internet transit or peering services to WeChat, or using the app’s code in other software or services in the US.

Those same prohibitions on providing services go into effect on November 12 for TikTok.

“Today’s actions prove once again that President Trump will do everything in his power to guarantee our national security and protect Americans from the threats of the Chinese Communist Party,” commerce secretary Wilbur Ross said in a statement.

The actions follow an August 6 executive order by the President, in which he argued that TikTok and WeChat collect data from American users that could be accessed by the Chinese government. The administration has threatened fines of up to $1 million and up to 20 years in prison for violations of the order.

TikTok is currently in talks to be acquired by the American software maker Oracle, and could announce a deal that assuages the administration’s national security concerns. In its announcement, the commerce department said that the President had given until November 12 for TikTok’s national security concerns to be resolved, and if they were, the prohibitions in the order could be lifted.

TikTok said in a statement: “We disagree with the decision from the Commerce Department, and are disappointed that it stands to block new app downloads from Sunday and ban use of the TikTok app in the US from Nov. 12. We will continue to challenge the unjust executive order, which was enacted without due process and threatens to deprive the American people and small businesses across the US of a significant platform for both a voice and livelihoods.”

Tencent and Oracle did not immediately respond to requests for comment. Ross, in an interview on Fox Business Network on Friday morning, said that the ban would initially have a much greater impact on WeChat.

“For all practical purposes it will be shut down in the US, but only in the US, as of midnight Monday,” Ross said.

TikTok would also face some changes, but would still be allowed to function until November 12, Ross said, at which point it would face the same ban as WeChat if there was no deal that satisfied the administration’s concerns. “As to TikTok, the only real change as of Sunday night will be users won’t have access to improved updated apps, upgraded apps or maintenance,” he said.

The prohibitions raise the question of whether Google and Apple, the major operators of American app stores, could sue the administration.

New York Times News Service and Reuters