“The decision to completely eliminate waivers was a surprise, as the market expectation was for a more gradual reduction,” Credit Suisse said in a research note.

The administration issued waivers to eight countries when it restored sanctions on Iran’s energy industry in November, allowing them to purchase limited quantities of Iranian crude. Five of the countries — China, India, Turkey, South Korea and Japan — took advantage of the exemptions.

The waivers allowed 1.4 million barrels per day of Iranian crude to flow to the market, down from about 2.5 million bpd last year. The new U.S. policy threatens to wipe out much of that supply at a time when the oil market is already tightening.