The United States on Monday will sanction more than two dozen people and entities involved in Iran's nuclear, missile and conventional arms programs, a senior U.S. official said, putting teeth behind U.N. sanctions on Tehran that Washington argues have resumed despite the opposition of allies and adversaries. Subscribe: http://smarturl.it/reuterssubscribe Reuters brings you the latest business, finance and breaking news video from around the globe. Our reputation for accuracy and impartiality is unparalleled. Get the latest news on: http://reuters.com/ Follow Reuters on Facebook: https://www.facebook.com/Reuters Follow Reuters on Twitter: https://twitter.com/Reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en