WASHINGTON, Aug 6 (Reuters) - The United States will impose a tariff of about 100% on semiconductor chips imported from countries not producing in America or planning to do so, President Donald Trump said.

Trump told reporters in the Oval Office on Wednesday the new tariff rate would apply to "all chips and semiconductors coming into the United States," but would not apply to companies that had made a commitment to manufacture in the United States.

"So 100% tariff on all chips and semiconductors coming into the United States. But if you've made a commitment to build (in the U.S.), or if you're in the process of building (in the U.S.), as many are, there is no tariff," Trump said.

It is not clear how many chips will be covered by the tariffs.

Congress created a $52.7 billion semiconductor manufacturing and research subsidy program in 2022. The Commerce Department last year under President Joe Biden convinced all five leading-edge semiconductor firms to locate chip factories in the U.S. as part of the program.

Last year the department said the U.S. produced about 12% of semiconductor chips globally, down from 40% in 1990.

Trump added: "If, for some reason, you say you're building and you don't build, then we go back and we add it up, it accumulates, and we charge you at a later date, you have to pay, and that's a guarantee."