President Donald Trump issued an executive order reinstating a "maximum pressure" campaign against Iran, targeting Tehran's oil exports.

Trump also directed his U.N. ambassador to work with allies to "complete the snapback of international sanctions and restrictions on Iran," under a 2015 deal between Iran and key world powers that lifted sanctions on Tehran in return for restrictions on its nuclear program.

US sanctions aim to cut Iran's oil exports, reducing revenue used for its nuclear program, missiles, and proxy groups.