President Donald Trump’s ban on TikTok was temporarily blocked by a federal judge, dealing a blow to the government in its showdown with the popular Chinese-owned app it says threatens national security.

US District Judge Carl Nichols granted a preliminary injunction against the ban on the widely used video-sharing network after an unusual Sunday morning hearing. The judge refused to grant an injunction against a November deadline for a sale. TikTok’s owner, ByteDance Ltd., had requested the hold after the president ordered TikTok out of American app stores unless the company sold a stake in its US operations to a domestic buyer.

The ban, scheduled to go into effect at 11:59 p.m. in New York, would have removed 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.

ByteDance is fighting the Trump administration in court even as it pursues its approval for the sale of a stake in the US business to Oracle Corp. and Walmart Inc. 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 he has taken on Beijing as the election approaches.

Even as the sale of TikTok is still awaiting final US approvals, two of China’s most prominent state-backed media mouthpieces last week denounced the deal.

“What the United States has done to TikTok is almost the same as a gangster forcing an unreasonable and unfair business deal on a legitimate company,” the state-run China Daily wrote in a Wednesday opinion piece. Hu Xijin, the influential editor-in-chief of the Party-run Global Times, tweeted that Beijing likely wouldn’t approve the current agreement as it endangered China’s national security.

A lawyer for TikTok told the judge at Sunday’s virtual hearing that the ban was irrational given that ByteDance is in talks to strike a deal the president himself has demanded.

“How does it make sense to impose this app-store ban tonight when there are negotiations underway that might make it unnecessary?” attorney John Hall asked.

Hall said banning TikTok from US 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. ByteDance says Trump is exceeding his authority with the ban.

“The consequences immediately are grave,” Hall told the judge. “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, citing its effect on free speech and the irreparable harm that the ban would cause to the business.

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.” The US government decided last week to extend its deadline to allow for more sale discussions.

In a filing on Friday, the US cited FBI Director Christopher Wray’s assessment that China poses the “greatest long-term threat to our nation’s information and intellectual property.”

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,” Schwei told the judge. “And I think the court owes significant deference to that.”

In a separate case, a federal judge in Pennsylvania on Saturday rejected a request by TikTok users to halt the ban, saying the consequences of the ban wouldn’t be severe enough for the users to justify an injunction temporarily blocking the order while the litigation continues.

The case is TikTok Inc. v. Trump, 20-cv-2658, US District Court, District of Columbia (Washington).