WASHINGTON (Reuters) - A growing number of lawmakers are urging President Joe Biden to grant a reprieve to prevent TikTok from going dark in the United States as soon as Sunday, warning millions of creators and businesses could be hurt.

"We're asking for the ability to be able to try rationally to resolve this issue so TikTok does not go dark," Democratic Senator Ed Markey said on Thursday. "Let's take a breath, try to step back, buy some time, try to figure this out."

Senate Democratic Leader Chuck Schumer spoke to Biden urging him to extend by 90 days a deadline for Chinese-owner ByteDance to sell TikTok U.S. assets and prevent a ban of the app used by 170 million Americans, an aide to Schumer said.

"It's clear that more time is needed to find an American buyer and not disrupt the lives and livelihoods of millions of Americans, of so many influencers who have built up a good network of followers," Schumer said.

Congress in April ordered ByteDance to sell TikTok within 270 days, citing national security concerns. The Justice Department said this month "TikTok's collection of reams of sensitive data about 170 million Americans and their contacts makes it a powerful tool for espionage" for China.

A White House official said on Thursday that given that the Jan. 19 deadline date is "over a holiday weekend a day before inauguration, it will be up to the next administration to implement." The White House previously said Biden did not plan to issue an extension.

On Wednesday, Reuters reported TikTok plans to shut U.S. operations of its social media app on Sunday, when a federal ban is set to take effect, barring a last-minute reprieve.

Markey and fellow Democratic senators Cory Booker and Chris Van Hollen wrote Biden asking him to grant an extension.

"Over the past few days, it has become clear that, without action from you, TikTok will likely go dark on Sunday, with serious consequences for the 170 million Americans and 7 million businesses that rely on TikTok," the senators wrote. "Your administration represents the last chance to avoid a TikTok shutdown on Sunday," they wrote.