The tariffs U.S. President Donald Trump imposed last week on dozens of countries are expected to remain in effect rather than be reduced during ongoing trade negotiations, U.S. Trade Representative Jamieson Greer said Sunday.

Watch Margaret Brennan's full interview with Jamieson Greer, the U.S. Trade Representative, a portion of which aired on "Face the Nation with Margaret Brennan" on.

"These tariff rates are pretty much set," Jamieson Greer said in an interview Friday with "Face the Nation with Margaret Brennan​."

U.S. Trade Representative Jamieson Greer spoke with Margaret Brennan on Face the Nation Sunday about tariff rates and sanctions.