U.S. House of Representatives Speaker Kevin McCarthy said on Sunday lawmakers will move forward with legislation to address national security worries about TikTok, alleging China’s government had access to the short video app’s user data.

In the United States, there are growing calls to ban TikTok, owned by China-based company ByteDance, or to pass bipartisan legislation to give President Joe Biden’s administration legal authority to seek a ban. Devices owned by the U.S. government were recently banned from having the app installed.

“The House will be moving forward with legislation to protect Americans from the technological tentacles of the Chinese Communist Party,” McCarthy said on Twitter.

TikTok CEO Shou Zi Chew appeared before a U.S. House Committee for about five hours on Thursday, and lawmakers from both parties grilled him about national security and other concerns involving the app, which has 150 million American users.

In Thursday’s hearing, the TikTok CEO was asked if of the app, has spied on Americans at Beijing’s request. Chew answered, “No.”

Republican Representative Neal Dunn then referenced the company’s disclosure in December that some China-based employees at ByteDance improperly accessed TikTok user data of two journalists and were no longer employed by the company. He repeated his question about whether ByteDance was spying.

“I don’t think that spying is the right way to describe it,” Chew said. He went on to describe the reports as involving an “internal investigation” before being cut off. McCarthy, a Republican, said in a tweet on Sunday, “It’s very concerning that the CEO of TikTok can’t be honest and admit what we already know to be true – China has access to TikTok user data.”

The company says it has spent more than $1.5 billion on data security efforts under the name “Project Texas” which currently has nearly 1,500 full-time employees and is contracted with Oracle Corp to store TikTok’s U.S. user data.

Rather than appease lawmakers’ concerns, Chew’s appearance before Congress on Thursday “actually increased the likelihood that Congress will take some action,” Representative Mike Gallagher of Wisconsin, the Republican chairman of the House Select Committee on the Chinese Communist Party, told ABC News on Sunday.

Former U.S. President Donald Trump lost a series of court rulings in 2020 when he sought to ban TikTok and another Chinese-owned app, WeChat, a unit of Tencent.

Many Democrats also have raised concerns although have not yet explicitly backed a U.S. ban.

Stay on top of technology and startup news that matters. Subscribe to our daily newsletter for the latest and must-read tech news, delivered straight to your inbox.