WASHINGTON: TikTok said the short-video sharing app now has 150 million monthly active users in the United States, up from 100 million it said it had in 2020.

The Chinese-owned app confirmed the figure ahead of TikTok CEO Shou Zi Chew's testimony set for Thursday before the House Energy and Commerce Committee.

On Friday, six more U.S. senators backed bipartisan legislation to give President Joe Biden new powers to ban TikTok on national security grounds. Last week, TikTok said the Biden administration demanded that its Chinese owners divest their stake in the app or it could face a U.S. ban.

The app faces growing pressure in Washington including calls to ban the app by many in Congress who fear its U.S. user data could fall into the hands of China's government. TikTok said in September 2021 that globally it had more than 1 billion monthly users.

Senate Intelligence Committee chair Mark Warner, who is cosponsoring legislation to give the administration more powers to ban TikTok, said at a Christian Science Monitor breakfast that he did not think TikTok U.S. data was safe.

"This notional idea that the data can be made safe under (Chinese Communist Party) law, just doesn't, doesn't pass the smell test."

TikTok said it has spent more than $1.5 billion on rigorous data security efforts, rejects spying allegations and said "if protecting national security is the objective, divestment doesn't solve the problem: a change in ownership would not impose any new restrictions on data flows or access."

The new figures are a sign of the app's wide popularity especially among younger Americans. Commerce Secretary Gina Raimondo told Bloomberg News there could be political ramifications to banning TikTok. "The politician in me thinks you’re gonna literally lose every voter under 35, forever," she said.

Some TikTok content creators will come to Washington this week to make the case why the app should not be banned.