The United States is considering additional sanctions against Iran that would hit areas not previously targeted, a senior Trump administration official told reporters on Monday.

The fresh sanctions would be enacted in May, a year after the U.S. withdrew from the 2015 Iran nuclear deal, reported Reuters.

“We just want a continued chilling effect,” said the official. “We want businesses to continue to think doing business with Iran is a terrible idea at this point.”

“The more we can do around the anniversary, the better,” added the official, who also said that it takes time for the U.S. Treasury Department to issue sanctions.

Finally, the official predicted that the United States will reduce the number of waivers it has given to several countries to import Iranian oil: “That, I think, is where we’re headed.”

The waivers were given after America reimposed sanctions in November that were lifted under the 2015 Iran nuclear deal.

Turkey, India, Japan, South Korea and China are likely to be given waivers after they expire in May that could limit Iranian crude oil exports at around 1.1 million barrels daily, while Greece, Taiwan and Italy would not be given another waiver.