Traders of oil in the Middle East and across the globe are facing supply and shipping issues after the United States announced the end of sanctions waivers for Iranian oil imports.

The Trump administration said yesterday (April 22nd 2019) that it would not be renewing exemptions granted last year and that all buyers of oil from Iran must stop purchases by May 1st or face sanctions themselves.

Sanctions on exports of Iranian oil were reimposed in November 2018 after US president Donald Trump pulled out of a 2015 agreement between Iran and six other nations that would have seen it limit its sensitive nuclear activities and permit inspections in return for sanctions relief.

However, China, India, Japan, South Korea, Taiwan, Turkey, Italy and Greece were granted six-month waivers against these sanctions - and it had been expected that they would be renewed this week, allowing importers to keep buying Iranian oil without penalties.

This has now been revealed not to be the case, with the White House saying it will instead be working with Saudi Arabia and the United Arab Emirates to keep the market "adequately supplied".

OPEC will no doubt be discussing the issue when it next meets in June, but crude prices have already hit a six-month high amid fears of a supply crunch.

Importers have also expressed concerns that, with many cargoes already booked for May delivery, they may not be able to get their supplies before the sanctions deadline.

Turkey has criticised the US's decision and commented that it will not be conducive to peace, while Iran insists the sanctions are illegal.

Iranian oil exports had already dropped to around one million barrels per day (bpd) after the sanctions were reimposed, down from more than 2.5 million bpd prior to this.

The decision could hit the country's economy particularly hard given that crude oil is one of its biggest sources of revenue.