Explainer-Trump wants more economic pressure on Iran. What are his options?

By Andrea Shalal WASHINGTON, Aug 16 (Reuters) - U.S. President Donald Trump on Friday vowed to hit Iran hard economically, a day after Treasury Secretary Scott Bessent said that Washington would impose measures on Tehran that have "never been seen" as soon as next week. The United States, ‌United Nations and European Union have applied sanctions, implemented trade embargoes and frozen assets since the late 1970s over Iran's nuclear program, human rights violations and support for militant…