WASHINGTON (Reuters) -Three Democratic senators on Monday urged the White House to seek authority from Congress to extend a deadline for China's ByteDance to sell popular social media app TikTok or result in its ban.

President Donald Trump in January unilaterally extended the sale deadline from January 19 to April 5.

"This nonenforcement of the TikTok ban was not only unlawful but also raised serious questions about TikTok's future," wrote Senators Ed Markey, Chris Van Hollen and Cory Booker, urging the president to back legislation to October.

"The path to saving TikTok should run through Capitol Hill."