(NewsNation) — TikTok’s CEO testified before Congress, defending their security and privacy policies as lawmakers consider banning the app over concerns about national security.

TikTok CEO Shou Chew told lawmakers that TikTok isn’t an agent of China, arguing the bottom line is that American data is stored on American soil. The company has spent more than $1 billion to make that so in efforts to convince the U.S. government that the app is safe and separate from the Chinese Communist Party.

Lawmakers opened the hearing by presenting concerns over TikTok’s privacy policies as well as concerns that the app can be used to spread disinformation and propaganda campaigns to influence American users. Concerns about the vulnerability of children and teens who may experience mental health impacts from social media were also brought up.

Chew defended the app’s actions, saying the company is working to be a good actor and protect privacy and safeguard young people.

“While the vast majority of people on TikTok are over 18 and one of our fastest growing demographics is people over 35,” Chew said.

Still, he said the app provides tools to protect youth, including limits on direct messages, limiting time spent on the app for users under 18 and offering family pairing tools to help parents control what their kids are exposed to.

Members of both parties pressed Chew hard on the dangers the app poses to children and teens, with a particular focus on dangerous challenges that have made headlines, like the so-called Blackout Challenge or Benadryl Challenge. Members also focused on algorithmic feeds surfacing harmful content or content designed to increase anxiety.

Chew defended TikTok’s content moderation tools as well as efforts to provide safety tools to users who search for certain terms, like suicide, which would surface safety information and resources.

Chew said TikTok is owned by global investors, not China, including American members of the board. He described the privacy situation as having a “firewall” around American data, stored on American soil by an American company, managed by American personnel. The company is in the process of deleting legacy data on American users and Chew said the process is expected to be complete this year.

Chew also defended the company’s efforts to be transparent in making source code available for review. He also pointed out the concerns about misinformation are not unique to TikTok and said uniform rules should be applied to all social media companies regardless of where they are based.

TikTok is not available in mainland China, but owner ByteDance is still headquartered in Beijing, and Chinese law dictates companies must provide user data if it deems it’s in the national interest of China. Chew testified that China has never asked for user data and TikTok has never provided data to the government.

But ByteDance acknowledges it has fired employees for accessing the data of U.S. journalists.

China is now weighing in, a spokesperson for the Ministry of Commerce saying the country “resolutely opposes” the forced sale of TikTok, adding it would “seriously damage investors from multiple countries including China” and would hurt “confidence to invest in the United States.”

These comments this morning from China could add fuel to the fire for lawmakers who are concerned that China is invested in TikTok as a potential tool to spy on Americans and spread misinformation.

The spokesperson did not say what Beijing would do, if anything, if President Joe Biden does force ByteDance to sell TikTok or face a nationwide ban.

Only two countries, India and Afghanistan, currently have bans on TikTok, though other countries have banned the use of the app on government devices due to security concerns. The U.S. has already banned TikTok on certain government devices, and some states are also moving forward with legislation restricting the app.

The White House is making that call. Members of both parties on Capitol Hill support legislation that empowers Biden to ban apps tied to adversaries due to credible threats to national security.