Trump said in a social media post that his tariffs are "the only reason" American cattle ranchers "are doing so well."

WASHINGTON (Reuters) -The administration of U.S. President Donald Trump on Wednesday continued its campaign to cut the cost of beef, with Trump urging cattle ranchers to lower prices while several agencies announced an effort to rebuild the country's decimated cattle herd.

The United States wants to keep out a flesh-eating parasite. But its strategy is costly for Mexico’s ranchers.