Ayatollah Ali Khamenei has spent almost four decades as Shi'ite Iran's supreme leader building a regional power to rival the Sunni states across the Gulf and implacably hostile to the U.S. and Israel - while crushing repeated unrest at home.

President Donald Trump opposed an Israeli plan to kill Iran’s Supreme Leader Ayatollah Ali Khamenei, according to two sources, amid ongoing waves of tit-for-tat strikes between Israel and Iran as the US president is making publicly and privately clear he prefers to keep the United States out of the fray for now.