A group of top Republican US Senators on Tuesday ramped up pressure on TikTok, asking the Trump administration to assess the threat that the popular Chinese-owned video-sharing app might meddle in the US elections.

In a letter dated Tuesday, Marco Rubio, Tom Cotton and other lawmakers cited alleged censorship by TikTok of sensitive content, including a video critical of China's treatment of Uighur minorities, as well as alleged attempts by Beijing to manipulate political discussions on social media apps...