May 4 (Reuters) – Advertisers are committed to continue spending on TikTok due to its immense popularity with users despite threats of a potential ban in the U.S. over national security concerns, ad experts said. The steadfastness comes as TikTok, which is owned by Chinese tech firm ByteDance, is fighting to prevent a ban in the U.S. after lawmakers introduced a bill that would grant President Joe Biden's administration authority to ban apps that pose security risks. The short-form video app has already been banned from government-issued phones in multiple countries. TikTok is set to host a presentation for advertisers…