The prohibition, which is set to begin at 11:59 p.m. Eastern Time, would remove TikTok from the app stores run by Apple Inc. and Google’s Android, the most widely used marketplaces for downloadable apps. People who don’t yet have the app wouldn’t be able to get it, and those who already have it wouldn’t have access to updates needed to ensure its safe and smooth operation. TikTok is used regularly by 19 million Americans.

The app’s owner, ByteDance Ltd., is fighting the Trump administration in court even as it pursues its approval for the sale of a stake in its U.S. operations to Oracle Corp. and Walmart Inc. under pressure from the president. Trump has called for bans on both TikTok and WeChat, owned by China’s Tencent Holdings Ltd., arguing that the apps could give China’s government access to millions of Americans’ personal data.

The bans are part of an increasingly hard line the president has taken on Beijing as the election approaches.

Read More: Trump Suffers Another Loss in the TikTok Showdown With China

At Sunday’s virtual hearing, Hall said banning TikTok from U.S. app stores would undermine security by preventing existing users from receiving weekly security updates. He argued that the government has less burdensome alternatives, such as the stake sale, to achieve its national-security aims.

“If that prohibition goes into effect at midnight tonight, the consequences immediately are grave,” Hall told U.S. District Judge Carl Nichols in Washington. “It would be no different than the government locking the doors to a public forum, roping off that town square.”

His language echoed the ruling of a judge in California who put a hold on Trump’s WeChat ban last week.

Daniel Schwei, a lawyer for the Justice Department, countered that “the concern here is about data security risk and leaving data vulnerable to the Chinese government. It is a threat today, it is a risk today, and therefore it deserves to be addressed today.”

Read More: U.S. Defends TikTok Ban With Saturday Ruling Against 3 Users

TikTok is “challenging a national security determination by the president as well as the judgment of the secretary of commerce about what’s necessary to mitigate those national security harms,” he said. “And I think the court owes significant deference to that.”

The judge gave little indication of whether he was leaning one way or the other as he questioned the lawyers. Nichols said he planned to issue a ruling “sometime later today but before 11:59 p.m.”

He said his order would be public but that he planned to keep the opinion explaining it under seal until a redacted version goes out on Monday. The U.S. filed papers under seal on Friday, saying they contained “confidential business information” about the app that ByteDance has shared with the Commerce Department.