WASHINGTON -- US President Donald Trump on Wednesday announced plans to impose 25-percent auto tariffs, with the measures set to take effect on April 2.

"What we're going to be doing is a 25-percent tariff for all cars that are not made in the United States," Trump said in the White House Oval Office. "We start off with a 2.5-percent base, which is what we're at, and go to 25 percent."

"We're signing (executive order) today. It goes into effect April 2. We start collecting on April 3," Trump said.

The US president argued that the tariffs would encourage more production to relocate to the United States, generate new revenue for the government, and help reduce the national debt.

Economists, however, have warned that tariffs would push up car prices, and hurt consumers, who already face elevated prices.