Members of Congress appeared unconvinced by TikTok CEO Shou Zi Chew's efforts in the House of Representatives to allay their fears about the popular social media platform's security and privacy risks.

Chew faced tough questions in the Energy and Commerce Committee for several hours Thursday about TikTok's parent company ByteDance and its relationship to China as well as about the app's risks to teenage mental health and data security. While Chew projected calm and moderation, he faced criticism from legislators and, by the end of the day, clearer threats to restrict TikTok within the United States.

"I was appalled by the TikTok CEO's response to my questions in the House Energy and Commerce Committee," Rep. Debbie Lesko (R-AZ), a member of the committee, told the Washington Examiner.

Lesko had asked Chew about his perspective on the Chinese persecution of the Uyghur people, but the CEO evaded the query. "His refusal to answer this question multiple times reveals that he and TikTok are under the influence of the Chinese government," Lesko said.

The sponsors of a leading anti-TikTok bill said that Chew's testimony added to their resolve. "Nothing we heard from Mr. Chew today assuaged [our] concerns," Sens. Mark Warner (D-VA) and John Thune (R-SD) said in a press statement. "It is vital for Congress to establish a process to review and mitigate the harms posed by foreign technology products that come from places like China and Russia."

Warner and Thune are the sponsors of the RESTRICT Act , a bill designed to give the Commerce Department additional powers to analyze and determine if a foreign business investment was a national security risk. The bill has several co-sponsors on both sides of the aisle. The RESTRICT Act is one of several bills introduced to limit or ban TikTok.

"It's beyond reckless for members of Congress to still be encouraging their constituents to use TikTok despite knowing the Chinese Communist Party is mining all their personal info," Sen. Thom Tillis (R-NC) said in a statement . "Protecting Americans from the CCP is more important than getting views. I call on all members of Congress to lead by example and stop using it."

The opposition to TikTok has continued to grow among Democratic lawmakers, although "Squad" member Rep. Jamaal Bowman has come out as a vocal supporter of the app .

The White House is pushing ByteDance to sell its stakes in the company or risk a national ban. Such a sale could be slowed by the Chinese government due to the need for it to be approved by CCP officials.