Janet Yellen said Monday that TikTok was discussed "briefly" in meetings with her counterparts in China — the latest sign that the prospect of a ban is rattling top officials in Beijing.

Why it matters: A bipartisan group of U.S. lawmakers is pushing legislation — recently passed by the House — that would require the popular video app to be spun off from its parent company, China-based ByteDance, or risk being banned.

• That possibility is the latest issue that could further stoke tensions over national security between the two global superpowers.

What they're saying: "We discussed it briefly," Yellen told reporters at a press conference early Monday, referring to TikTok.

• Yellen said the U.S. was worried about protecting sensitive personal data, calling it a "legitimate concern."
• "I am certainly supportive of efforts by our administration to address national security issues that relate to sensitive personal data," Yellen said.
• "China, for its part, is also concerned about many social apps that are not allowed to operate in China," Yellen added. "We would like to find a way forward. Of course this is important to the Chinese."
• Yellen emphasized that President Biden had indicated support for the legislation to crack down on TikTok.

The big picture: In remarks on Monday, Yellen said it was "undeniable" that the U.S-China relationship is on "stronger footing that this time last year."

• That's despite tough talk about the risk that Yellen said the heavy subsidization of China's manufacturing sector poses to the global economy.

Zoom in: Yellen also said she raised concerns over the role that firms, including those in China, are playing in aiding Russia in the war in Ukraine.

• "I stressed that companies, including those [China], must not provide material support for Russia's war and that they will face significant consequences if they do," Yellen said.
• She warned that any banks that "facilitate significant transactions" to funnel goods helping Russia's defense "expose themselves to the risk of U.S. sanctions."

Go deeper: Yellen says cutting off economic relations with China isn't "practical"