The foreign chiefs of the United States, Japan and South Korea expressed expectations Thursday for substantial progress on North Korea's denuclearization, aiming to work together in a process that U.S. Secretary of State Mike Pompeo said may not be easy.As the foreign chiefs reaffirmed the importance of trilateral cooperation, Pompeo said the United States is committed to "complete, verifiable, and irreversible" denuclearization of the Korean Peninsula.Pompeo, who has led U.S. negotiations with North Korea, said its leader Kim Jong Un understands "the urgency" of denuclearization of the pen…READ FULL ARTICLE