The US Department of Agriculture has suspended the transport of live cattle, horses and bison through ports of entry along the border with Mexico for at least two weeks. It’s part of an effort to curb the spread of New World screwworm,

Because the New World screwworm has been detected in southern Mexico and is spreading north, the U.S. is halting live cattle, horse and bison imports from Mexico, on the orders of U.S. Department of Agriculture Secretary Brooke Rollins.

The latest halt in cattle imports via the U.S.-Mexico border comes only months after imports were stopped due to the same reason.