WASHINGTON — A bipartisan group of senators hopes to block importation of livestock from Argentina until it’s clear the nation is free of foot-and-mouth disease.

South Dakota Sen. Tim Johnson, a Democrat, and Wyoming Sen. Mike Enzi, a Republican, introduced legislation Thursday to prevent livestock importation from Argentina until the U.S. Department of Agriculture can certify that it’s safe.

The region has seen outbreaks of the highly contagious disease that affects cloven-hoofed animals like cattle and pigs. It is a viral illness that can be spread through even minimal contact with infected animals, farm equipment or meat. It can be fatal to animals, but does not harm humans.

Johnson and Enzi said they introduced the bill after hearing from concerned farmers and ranchers about the safety of their livestock. Senators from Montana, North Dakota, New Mexico, Colorado and Missouri co-sponsored the legislation.

‘‘Foot-and-mouth disease is a highly contagious and destructive disease, and we cannot risk the health of our livestock herds for questionable imports from Argentina,’’ said Johnson.

The Department of Agriculture proposed last year to expand beef imports from one region of Argentina. The United States has been free of the disease since 1929.

Rep. Stephanie Herseth, D-S.D., said Thursday that she and Rep. Barbara Cubin, R-Wyo., plan to introduce a similar bill in the House next week.