The United States has responded angrily after Iran's Supreme Leader used his first sermon in eight years to call President Trump a clown.

Leading Friday prayers in Tehran, Ayatollah Khamenei accused Mr Trump of only pretending to support the Iranian people and would "push a poisonous dagger" into their back.

US Special Representative for Iran, Brian Hook speaks to Sky News.

Code: SPORTDX. Promo code is required. Discount is applied only to a certain category of goods.

More videos