The U.S. has closed its southern border again to livestock imports, saying a flesh-eating parasite has moved further north in Mexico than previously reported. Mexico's president was critical Thursday,

The U.S. has shut its southern border to livestock imports again after a flesh-eating parasite was found further north in Mexico than previously reported, raising alarm among American agriculture officials.

The US has closed its southern border to livestock imports, citing the spread of the New World screwworm fly in Mexico. While Mexico argues the move is exaggerated, US officials fear economic losses if the parasite reaches Texas.