Chicago | Reuters — Chicago Mercantile Exchange cattle and hog futures fell on Friday, pressured by fears that Mexico, a key importer of both U.S. beef and pork, will retaliate against President Donald Trump’s proposal to impose tariffs on imports from Mexico.

The fresh trade concerns, coming at a time when U.S. supplies of both hogs and cattle are outstripping demand, outweighed a bullish weekly report on export sales and pushed feeder cattle futures to their lowest in a year.

“I think we got a kicker to the downside with the new five per cent tariff proposal that looks like it is going to go in effect in June,” said Don Roose, president of brokerage U.S. Commodities in West Des Moines, Iowa.

Trump, responding to a surge of migrants across the southern border, vowed on Thursday to impose a tariff on all goods coming from Mexico, starting at five per cent and ratcheting much higher until the flow of people ceases.

Mexico is the biggest importer of U.S. pork and the third biggest importer of U.S. beef.

August feeder cattle finished down 5.1 cents at 133.125 cents/lb. and September feeders fell 4.45 cents to 134.075 cents (all figures US$).

The front-month contract hit its lowest since May 18, 2018 on a continuous basis.

June live cattle dropped 1.6 cents to 108.475 cents/lb., and actively traded August fell 1.975 cents to 103.075 cents.

The front-month live cattle contract hit its lowest since Aug. 31, 2018.

CME June lean hogs closed down 1.95 cents at 81.725 cents/lb. while actively traded July hogs ended down 1.95 cents at 85.925 cents.

USDA on Friday morning said weekly pork export sales totaled 54,700 tonnes, up from 46,300 tonnes a week ago. The weekly total included 8,900 tonnes to Mexico.

Beef export sales were 21,800 tonnes in the latest week compared to 24,400 tonnes last week but 14 per cent above the average of the previous four weeks.

— Mark Weinraub is a Reuters commodities correspondent in Chicago.