WASHINGTON (Reuters) -President Donald Trump said on Tuesday that the United States would initially place a "small tariff" on pharmaceutical imports before hiking it to 150% within 18 months and eventually to 250% in an effort to boost domestic production.

"In one year, one and a half years maximum, it's going to go to 150% and then it's going to go to 250% because we want pharmaceuticals made in our country," Trump told CNBC in an interview.

He did not specify the initial tariff rate on pharmaceuticals. Trump said earlier this month that pharmaceutical tariffs could reach as high as 200%.

Trump also said he plans to announce tariffs on semiconductors and chips in the "next week or so," but gave no further details.

The United States has been conducting a national security review of the pharmaceutical sector, and the industry has been preparing for possible sector-specific tariffs. The administration has not announced when the results of that probe will be released.

A framework agreement between the United States and the EU sets out that tariffs on pharmaceuticals and semiconductors are currently zero, but if the United States raises tariffs following its import investigation, they will be capped at 15%.