US President Donald Trump has decided to end exemptions from sanctions for countries still buying oil from Iran. The White House said waivers for China, India, Japan, South Korea and Turkey would expire in May, after which they could face US sanctions themselves. This decision is intended to bring Iran’s oil exports to zero, denying the government its main source of revenue. Iran insisted the sanctions were illegal and that it had attached “no value or credibility” to the waivers. Mr Trump reinstated the sanctions last year after abandoning a landmark 2015 nuclear deal between Iran and six world powers.