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 closed its southern border again to livestock imports, saying a flesh-eating parasite has moved further north in Mexico than previously reported

A parasitic fly known as the New World Screwworm has been located 400 miles from the U.S. border causing concern in the agriculture industry.