The United States and South Korea signed an agreement on Friday to set up a monitoring system to warn of biological weapons attacks by North Korea, South Korea’s defense ministry announced on Sunday.

The agreement, which was signed at the U.S. Army Medical Research and Materiel Command in Washington DC, was signed by Lee Nam-woo, a defense ministry official, and Carmen Spencer, the Joint Program Executive Officer for Chemical and Biological Defense.

A spokesman from the Republic of Korea’s defense ministry said that the United States and South Korea agree that “we need to be prepared for the potential use of biological weapons by