This preliminary ruling is on top of duties imposed in November to offset the 2-7 percent subsidies Spanish exporters benefited from.
The action is part of President Donald Trump's aggressive defense of US trade interests, with anti-dumping and countervailing duty actions up 61 percent since he took office, according to the Commerce Department.
The Commerce Department is set to announce its final decision on the antidumping case against Spanish olives on June 5th, while the final ruling on the earlier countervailing duties decision is due in May.
The rulings will be subject to review by the International Trade Commission on whether US producers were hurt.
But meanwhile, US customs agents will collect cash deposits on olive imports based on the rates, according to the Commerce Department.
In 2016, the US imported an estimated $70.9 million worth of ripe Spanish olives, principally from producers in Seville.