Farmers and meat producers across the U.S. can expect the new tariffs on Mexico, Canada and China and the retaliation to hurt their bottom lines by billions of dollars if they stay in place a while.

President Donald Trump is asking American growers to bear with him as tariffs threaten to hurt their business and deepen a farm downturn that’s entering a third year.

As tariffs take effect, farmers fear retaliation from other countries will impede their exports and drive up costs of production.