(CNN Business) TikTok repeatedly declined to commit to US lawmakers on Wednesday that the short-form video app will cut off flows of US user data to China, instead promising that the outcome of its negotiations with the US government "will satisfy all national security concerns." Testifying before the Senate Homeland Security Committee, TikTok Chief Operating Officer Vanessa Pappas first sparred with Sen. Rob Portman over details of TikTok's corporate structure before being confronted — twice — with a specific request. "Will TikTok commit to cutting off all data and data flows to China, China-based TikTok employees, ByteDance employees, or any…