WASHINGTON (Reuters) -A bipartisan group of U.S. lawmakers are introducing legislation on Tuesday that would give China's ByteDance about six months to divest popular short video app TikTok or face a U.S. ban, congressional aides told reporters.

Representative Mike Gallagher, the chair of the House select China committee and Representative Raja Krishnamoorthi, the top Democrat, are introducing legislation joined by more than a dozen other lawmakers to address national security concerns posed by Chinese ownership of the app.

The bill would give ByteDance 165 days to divest TikTok, which is used by more than 170 million Americans, or it would be unlawful for app stores operated by Apple, Google and others to offer TikTok or to provide web hosting services to ByteDance-controlled applications.

The bill would give the president new powers to designate apps of concern and face bans or restrictions absent divestiture.

Concerns about Chinese-owned TikTok last year sparked efforts in Congress to boost powers to address the popular short video sharing app or potentially ban it, but those prior bills have stalled.

The White House backed legislation sponsored by Senator Mark Warner and more than two dozen other senators introduced last year to give the administration new powers to ban TikTok and other foreign-based technologies if they pose national security threats.

The U.S. Treasury-led Committee on Foreign Investment in the United States (CFIUS) in March 2023 demanded that TikTok's Chinese owners sell their shares, or face the possibility of the app being banned, Reuters and other outlets reported, but the administration has taken no action.

The new bill is aimed at bolstering the legal authority to address TikTok concerns. Biden's predecessor, Republican Donald Trump, tried to ban TikTok in 2020 but was blocked by U.S. courts.

Other Chinese non-social media apps, such as those run by retailers Shein and Temu, would not be covered under the bill, aides said.