What Western Hemisphere Nation was prompted by Germany to fight the US in World War 1?

Mexico was the Western Hemisphere nation prompted by Germany to fight the United States in World War I. This occurred through the Zimmermann Telegram, in which Germany proposed a military alliance with Mexico against the U.S., promising to support Mexico in reclaiming lost territories such as Texas, New Mexico, and Arizona. The revelation of this telegram helped galvanize U.S. public opinion in favor of entering the war. Ultimately, the U.S. declared war on Germany in April 1917.