Crude oil markets had been pricing in the potential of a US exit from the Iran nuclear deal heading into the speech in which US President Donald Trump confirmed his country would pull out, but oil prices rose further when renewed US action against Iran was confirmed.
Organisation of the Petroleum Exporting Countries (OPEC) has a deal with some non-OPEC countries, such as Russia, to reduce oil output in an attempt to curb the oversupply of crude in the global market. Current agreements keep the output curbs in place until December 2018, with a meeting scheduled to review these production agreements in June. OPEC thinks the oversupplied global market will rebalance as soon as June 2018, and the news of US sanctions on Iran will perhaps provide further credence to this forecast. The US decision on Iran will also raise fears about increased geopolitical tensions in the Middle East, which would equate to further supply constraints and a further catalyst for oil prices.