April 6 (Reuters) - Two U.S. senators proposing to give the Biden administration new powers to ban Chinese-owned short video app TikTok on Thursday rejected criticism arguing it is the best way to address security concerns about a broad range of foreign-owned apps. Senators Mark Warner, a Democrat and John Thune, a Republican, last month proposed the Restrict Act that would grant the Commerce Department new authority to review, block, and address a range of transactions involving foreign information and communications technology that pose national security risks. "Our bill is designed to modernize the president’s international economic authorities for the...