Washington, Sept. 23 -- The United States joined Argentina, Bolivia, Chile, Colombia, Costa Rica, the Dominican Republic, Ecuador, El Salvador, Guyana, Honduras, Panama, Paraguay, Peru and Trinidad and Tobago in unveiling a new regional security and economic initiative dubbed the "Shield of the Americas," aimed at countering narco-terrorist networks across the Western Hemisphere.

In a joint statement, the 15 governments said they intended "to strengthen the resilience of the Western Hemisphere" through three pillars: economic cooperation, security, and multilateral coordination.

On the economic front, the countries pledged to defend their economies "by enhancing economic cooperation; exploring investment screening mechanisms; safeguarding...